9. 权限系统

00:01 The following content is provided under a Creative Commons license. 以下内容在知识共享许可下提供。 00:04 Your support will help MIT OpenCourseWare 你的支持将帮助MIT开放课程。 00:07 continue to offer high quality educational resources for free. 继续免费提供高质量的教育资源。 00:11 To make a donation or to view additional materials 要捐款或查看其他材料 00:13 from hundreds of MIT courses, visit MIT OpenCourseWare at ocw.mit.edu. 来自数百门MIT课程，请访问MIT开放课程网站ocw.mit.edu。 00:23 PROFESSOR: Welcome back. 教授：欢迎回来。 00:26 I know we're sort of getting into the middle of the week. 我知道我们已经进入了周中的阶段。 00:30 Some of you maybe want to keep your laptops open to work 你们中的一些人可能想打开笔记本电脑来处理 00:33 on other courses' midterms, but I 其他课程的期中考试，但我 00:35 will ask you to try to focus on Blockchain and Money today. 会请你们今天专注于区块链和货币。 00:43 Today, we're going to chat about permissioned versus permissionless systems. 今天，我们将讨论许可系统与无许可系统。 00:48 I want to thank-- I have a guest here. 我想感谢——我这里有一位嘉宾。 00:51 I call out guest when they're here and I know them. 当他们在这里并且我认识他们时，我会提到嘉宾。 00:53 Mark Snyderman, who runs a fund at Fidelity-- Mark runs a 6-- about $6 billion? 马克·斯奈德曼，他在富达管理一个基金——马克管理着一个大约60亿美元的基金？ 01:02 Called the Real Estate Income Fund at Fidelity. 叫做富达房地产收入基金。 01:05 And you might say, well, why does 你可能会问，为什么他 01:07 he want to come to a Blockchain and Money course? 想来上区块链和货币课程？ 01:09 It's because we went to high school together. 因为我们是高中同学。 01:11 [LAUGHTER] So-- and I was at his wedding. [笑声] 所以——我参加了他的婚礼。 01:19 And he's getting married again next week. 他下周要再婚。 01:23 Yeah. 是的。 01:23 [APPLAUSE] But you can all inundate Mark later about Fidelity, [掌声] 但你们可以稍后向马克询问关于富达的事， 01:32 because he's been there for a lot of years. 因为他在那里工作了很多年。 01:35 See what I'm going to do? 你们看我接下来要做什么？ 01:37 I'm shamelessly for MIT and MIT students. 我毫不掩饰地支持MIT和MIT的学生。 01:42 So let's get going. 那么我们开始吧。 01:45 I was letting a little bit of time for a few more people to wander in. 我留了一点时间让更多的人进来。 01:50 Today, we're going to talk-- 今天，我们将讨论—— 01:52 of course, we're going to chat a little bit about the readings 当然，我们将稍微讨论一下阅读材料 01:54 and study questions. 和学习问题。 01:56 Going to go back again to, what are the technical and commercial challenges? 我们将再次回到，技术和商业挑战是什么？ 02:00 And this is relative-- this is relevant for all of our lectures, 这与所有讲座相关， 02:04 but it's particularly relevant today, 但今天特别相关， 02:06 because we're going to be talking about two different database structures. 因为我们将讨论两种不同的数据库结构。 02:11 One's the permissionless blockchain of Bitcoin. 一种是比特币的无许可区块链。 02:14 But now, today, we're going to introduce and go deeper 但今天，我们将介绍并深入探讨 02:17 into the permissioned, or private, set of blockchains, 许可或私有区块链集， 02:21 like the IBM Hyperledger and Corda. 例如IBM Hyperledger和Corda。 02:25 But the technical issues relate to all of that. 但技术问题与所有这些相关。 02:30 And then, of course, we're going to talk 然后，当然，我们将讨论 02:31 about that against a third type of database-- traditional databases. 与第三种类型的数据库——传统数据库进行比较。 02:37 So aligning permissionless, like Bitcoin, permissioned-- 因此，将无许可的（如比特币）、许可的—— 02:43 IBM Hyperledger type of-- IBM Hyperledger类型的—— 02:46 and then traditional databases, and why, in a business setting, 以及传统数据库，以及在商业环境中，为什么 02:49 you might think of one versus another versus another. 你可能会考虑一种而不是另一种。 02:53 And I'm sure if I run off the rails anywhere 我相信如果我在任何地方偏离了主题 02:56 on traditional databases, which I have not personally studied, 关于传统数据库，我个人并没有研究过， 02:59 Alon will help bail me out somewhere. 阿隆会在某个地方帮我解围。 03:02 Is that a deal? 可以吗？ 03:03 Maybe? 也许？ 03:04 AUDIENCE: OK. 观众：好的。 03:04 PROFESSOR: All right. 教授：好的。 03:05 [LAUGHTER] AUDIENCE: You asked for it. [笑声] 观众：你要求的。 03:08 PROFESSOR: Yeah, I asked for it. 教授：是的，我要求的。 03:10 Mark, Alon is a computer scientists 马克，阿隆是一位计算机科学家 03:13 from other parts of MIT, so he helps me out in subjects 来自MIT的其他部门，所以他在我不懂的科目上帮助我 03:17 I don't know, and even in subjects I think I know. 甚至在我认为我知道的科目上。 03:25 So let's just start a little bit with what did you take from the readings? 那么我们先从你们从阅读材料中得到了什么开始？ 03:29 There were four or five readings, of course. 当然，有四到五篇阅读材料。 03:31 But what is a permissioned or private distributed ledger? 但什么是许可或私有的分布式账本？ 03:35 Now, I can do this. 现在，我可以这样做。 03:37 I can light them up, as some people said, because Toledo's given me my list. 我可以点名他们，正如一些人所说，因为托莱多给了我名单。 03:43 But again, class participation-- anybody who hasn't spoken yet 但再次强调，课堂参与——任何还没有发言的人 03:47 might want to sort of chime in and give it a shot. 可能想要插话并试一试。 03:51 I'm not seeing any volunteers. 我没有看到任何志愿者。 03:53 If I can-- ooh, yes. 如果可以的话——哦，是的。 03:55 Do you want to tell me your first name again? 你想再告诉我你的名字吗？ 03:57 AUDIENCE: Jayati 观众：Jayati PROFESSOR: Jayati. 教授：Jayati。 03:59 AUDIENCE: Jayati. 观众：Jayati。 04:00 PROFESSOR: OK. 教授：好的。 04:02 AUDIENCE: So the permissioned DODs, unlike the permissioned [INAUDIBLE] Bitcoin, 观众：所以许可的DOD，与许可的[听不清]比特币不同， 04:11 they limit the number of participants. 它们限制参与者的数量。 04:13 Essentially, they require the participants 本质上，它们要求参与者 04:15 to be authorized before they can enter into this sort of technology. 在进入这种技术之前必须获得授权。 04:21 And in addition to that, they are said to be stakeholders. 此外，它们被称为利益相关者。 04:25 And since they are the only ones involved in verifying the transaction-- 由于他们是唯一参与验证交易的人—— 04:30 unlike the permissionless ones, where it has to be verified at all the nodes, 与无需许可的情况不同，后者必须在所有节点上进行验证， 04:35 this limits the permissions required [INAUDIBLE] stakeholders, which increases, 这限制了所需的权限[听不清]利益相关者，从而提高了， 04:42 also, the transaction speed. 同时也提高了交易速度。 04:44 So it's like the triangular dilemma 所以这就像我们学到的三角困境 04:48 we learned about, about the security and decentralization and scalability. 关于安全性、去中心化和可扩展性。 04:53 So it moves away from decentralization and towards scalability. 因此，它远离去中心化，朝着可扩展性发展。 04:57 PROFESSOR: OK. 教授：好的。 04:58 So Jayeta-- 所以Jayeta—— 05:03 AUDIENCE: Jayehta. 观众：Jayehta。 05:07 PROFESSOR: Jayeta went through a whole lot. 教授：Jayeta讲了很多内容。 05:10 It's about the number of nodes and permissioned 这是关于节点数量和许可的 05:17 into it, and that it addresses some of that Buterin's trilemma. 以及它解决了Buterin的三难困境的一些问题。 05:22 So at its core, it sort of addresses some of the scalability issues. 所以从本质上讲，它解决了一些可扩展性问题。 05:26 But it does that at a trade off that it's not truly open. 但这样做的代价是它并不是真正开放的。 05:29 It's not, anyone can write to the ledger. 并不是任何人都可以写入账本。 05:31 I mean, that's sort of the fundamental things. 我的意思是，这就是基本的事情。 05:35 Anything else that folks took out of the core readings 还有其他人从核心阅读中得出的结论吗 05:39 as to how it separates and how it's different? 关于它是如何分开的以及它有什么不同？ 05:41 I mean-- all right. 我的意思是——好吧。 05:44 We'll get a chance to add a little bit. 我们将有机会补充一些内容。 05:51 And then we're going to dive into Hyperledger and Corda a bit. 然后我们将稍微深入了解Hyperledger和Corda。 05:53 We'll talk about Digital Asset Holdings. 我们将讨论数字资产控股公司。 05:54 What's Digital Asset Holdings? 什么是数字资产控股公司？ 05:59 Anybody know this company? 有人知道这家公司吗？ 06:00 Alon knows it. Alon知道。 06:02 Brotish knows it. Brotish知道。 06:03 Eilon. Eilon。 06:05 AUDIENCE: Yeah. 观众：是的。 06:08 It's basically a competitor of [INAUDIBLE].. 它基本上是[听不清]的竞争对手。 06:10 They're trying to build a DLT protocol that 他们试图建立一个DLT协议， 06:12 will allow financial institutions to exchange information and value. 以便金融机构能够交换信息和价值。 06:17 And they started, to my understanding, 据我了解，他们在2016年开始， 06:19 in 2016, which is two years after R3 Corda funded 这比R3 Corda获得资金的时间晚了两年， 06:23 by [INAUDIBLE] JPMorgan, Goldman Sachs. 由[听不清]摩根大通、美国银行资助。 06:27 They're basically the same amount of money-- $110 million. 他们基本上获得了相同数量的资金——1.1亿美元。 06:30 PROFESSOR: And who, other than Alon can tell me who runs Digital Asset Holdings? 教授：除了Alon，还有谁能告诉我谁在运营数字资产控股公司？ 06:36 Just, it shows that you did the reading. 这表明你做了阅读。 06:39 Somebody out there. 有人在那儿。 06:40 Yes. 是的。 06:41 Priya? Priya？ 06:41 AUDIENCE: It was-- 观众：是—— 06:42 AUDIENCE: Priya. 观众：Priya。 06:43 AUDIENCE: Yes. 观众：是的。 06:47 Blythe Mas-- Blythe Masters, or Blythe-- Blythe Mas——Blythe Masters，或者Blythe—— 06:47 PROFESSOR: Blythe Masters. 教授：Blythe Masters。 06:48 AUDIENCE: Yes. 观众：是的。 06:50 PROFESSOR: All right. 教授：好的。 06:54 Does anybody know who Blythe Masters is 有人知道Blythe Masters是谁吗 07:02 and what she's famous for beyond Digital Asset Holdings? 以及她在数字资产控股公司之外因为什么而出名？ 07:04 AUDIENCE: She worked at JPMorgan, and she [INAUDIBLE] credit default swaps. 观众：她曾在摩根大通工作，并且她[听不清]信用违约掉期。 07:08 PROFESSOR: So she worked at JPMorgan, 教授：所以她曾在摩根大通工作， 07:12 and she's known around the world of credit default swaps. 她在信用违约掉期领域是众所周知的。 07:16 Gillian Tett, who some of you-- the Sloan Fellows will get a chance Gillian Tett，一些人——斯隆研究员将在几周后有机会 07:21 to chat with Gillian Tett in New York in a few weeks. 在纽约与Gillian Tett交谈。 07:27 Gillian Tett wrote a whole book about credit default swaps and JPMorgan. Gillian Tett写了一整本关于信用违约掉期和摩根大通的书。 07:29 And Blythe Masters is a central character in that whole narrative art. 而Blythe Masters是整个叙述中的核心人物。 07:34 And this is what she's doing now. 这就是她现在所做的。 07:36 She's brilliant, and she's a very good businesswoman. 她很聪明，是一位非常优秀的女商人。 07:39 I ran the Commodity Futures Trading Commission 我曾担任商品期货交易委员会的主席， 07:41 and had an opportunity to meet with her a lot 并有机会与她多次会面。 07:39 because she ran the swap dealer association ISDA at the time, 因为她当时负责掉期交易商协会ISDA， 07:45 or was the outside chair of ISDA, if I recall. 或者如果我没记错的话，她是ISDA的外部主席。 07:50 And then we're going to talk about the business trade-offs as well. 然后我们还将讨论商业权衡。 07:55 But what do you think some of the central business 但是你认为一些核心商业 07:57 trade-offs, if I could get two or three of you 权衡是什么，如果我能请你们中的两三位 07:59 to help me out on what are the central business 来帮我解答一下核心商业 08:01 trade-offs between permissioned and permissionless blockchains? 在许可链和无许可链之间的权衡？ 08:09 Let me see if I can get somebody other than Pria. 让我看看我能否请到其他人而不是Pria。 08:11 Yes. 好的。 08:12 Remind me of your first name. 请提醒我你的名字。 08:14 AUDIENCE: Misha. 观众：Misha。 08:15 So permissioned blockchain have better privacy and protection, 所以许可链具有更好的隐私和保护， 08:20 and better scalability. 以及更好的可扩展性。 08:22 And no mining [INAUDIBLE]. 并且没有挖矿[听不清]。 08:25 PROFESSOR: Misha, let's pause for a minute. 教授：Misha，让我们暂停一下。 08:27 So better scalability, better privacy, and the third point you're saying? 所以更好的可扩展性，更好的隐私，以及你说的第三点是什么？ 08:33 AUDIENCE: No mining. 观众：没有挖矿。 08:34 PROFESSOR: No mining. 教授：没有挖矿。 08:35 Or, mining is associated with this proof of work. 或者，挖矿与工作量证明相关。 08:39 Any other business trade-off? 还有其他商业权衡吗？ 08:41 AUDIENCE: So for permissioned, you have some more flexibility with governance. 观众：所以对于许可链，你在治理上有更多的灵活性。 08:45 If you need to make changes, you don't need to rely [INAUDIBLE].. 如果你需要进行更改，你不需要依赖[听不清]。 08:48 PROFESSOR: So more flexibility of governance, in essence, 教授：所以本质上是治理的灵活性更高， 08:51 because if you have a club deal or group deal, maybe 因为如果你有一个俱乐部交易或团体交易，也许 08:54 you can do that governance changes 你可以在小组内进行治理更改 08:57 amongst the group instead of having thousands of people participating. 而不是让成千上万的人参与。 09:03 Kelly? Kelly？ 09:03 AUDIENCE: There's also a key technological differentiator, 观众：还有一个关键的技术差异， 09:07 which is the coding language sort of that the inputs can be made in. 那就是输入可以使用的编程语言。 09:11 So with Hyperledger, they can use the smart contacts 所以在Hyperledger中，他们可以使用智能合约 09:15 in any variety of them, versus the alternative, which is 以各种形式，而替代方案是 09:20 the domain specific language. 领域特定语言。 09:22 PROFESSOR: Right. 教授：对。 09:23 So Hyperledger at least promotes themselves in their own 所以Hyperledger至少在他们自己的 09:27 write-ups-- because the reading was really from them-- 文献中宣传自己——因为阅读材料确实来自他们—— 09:31 that their embedded language is much more flexible, 他们的嵌入式语言更加灵活， 09:36 and that you can use Java, you can use Go, and so forth-- 而且你可以使用Java，可以使用Go等等—— 09:40 at least they say they can. 至少他们说他们可以。 09:42 I don't know if it's really as limited in Ethereum. 我不知道在以太坊中是否真的如此有限。 09:46 But they think and they promote that they're more flexible than Ethereum. 但他们认为并宣传他们比以太坊更灵活。 09:51 So Kelly's right in that, too. 所以Kelly在这方面也是对的。 09:56 So these were the readings. 所以这些是阅读材料。 09:57 And now, so we're back to basics again. 现在，我们又回到了基础知识。 10:00 What is a blockchain? 区块链是什么？ 10:03 I know we've spent four or five lectures on it, 我知道我们已经花了四五节课来讲这个， 10:05 but these key components-- let's start. 但这些关键组成部分——我们开始吧。 10:09 Append-only timestamped logs. 仅追加的时间戳日志。 10:13 Are they both-- by show of hands, are they in permissionless blockchains? 它们都在——请举手，它们在无许可链中吗？ 10:20 I hope every single hand goes up. 我希望每一只手都能举起来。 10:24 Are they in permissioned or closed blockchains? 它们在许可链或封闭链中吗？ 10:33 I'm watching. 我在观察。 10:33 I'm not-- I'm just going to watch. 我不——我只是想观察。 10:35 All right. 好的。 10:36 Every hand should go up. 每只手都应该举起来。 10:38 So both sets of blockchains have this concept 所以这两类区块链都有这个概念 10:42 that goes back nearly 30 years to our friend 可以追溯到近30年前我们的朋友 10:45 Haber, who started the whole blockchain that's in The New York Times. Haber，他开启了《纽约时报》中的整个区块链。 10:53 This whole concept is in both sets of blockchains. 这个概念在这两类区块链中都存在。 10:56 Brotish? Brotish？ 10:57 AUDIENCE: So I have a question about basically 观众：所以我有一个问题，基本上是关于 10:58 kind of [INAUDIBLE] append-only [INAUDIBLE] of the ledger. 某种[听不清]仅追加[听不清]的账本。 11:04 I think I read in one of the readings that Corda has a feature where you 我想我在其中一篇阅读材料中读到Corda有一个功能，你可以 11:07 can make some changes to the history, which is not 对历史进行一些更改，这并不是 11:11 equivalent to a hard fault. So that will probably 等同于硬分叉。所以这可能 11:14 be one example where it is not purely append-only in a permission [INAUDIBLE].. 是一个例子，在一个许可[听不清]中并不是纯粹的仅追加。 11:18 PROFESSOR: So Brotish is raising that there's certain features that are promoted 教授：所以Brotish提到有一些功能在某些私有区块链中被推广 11:26 that may allow you not to append-only, but in essence, 这可能允许你不仅仅是追加，而在本质上， 11:31 delete data, or replace data, possibly. 删除数据，或者可能替换数据。 11:38 And I'm not-- because there's also, in private blockchains, 我不确定——因为在私有区块链中也存在， 11:42 an inability to partition, and in essence, sh-- 无法进行分区，本质上，sh—— 11:46 it's kind of a form of shorting-- but to partition the data. 这有点像一种做空的形式——但要对数据进行分区。 11:51 I don't know enough about Corda, whether they literally allow you to delete-- 我对Corda了解不够，不知道他们是否真的允许你删除—— 11:56 or is it something in this partitioning? 还是这与分区有关？ 11:58 But maybe Hugo? 但也许可以问Hugo？ 12:00 AUDIENCE: I was going to raise a similar point that if-- 观众：我想提出一个类似的观点，如果—— 12:03 I mean, to my understanding, if you have a permissioned system 我的理解是，如果你有一个许可系统， 12:07 and there are only a small number of-- we'll still 而且只有少数几个——我们仍然会 12:10 call them nodes, then if you realize you did something 称它们为节点，那么如果你意识到你做错了什么， 12:14 wrong, or something needs to be changed, can't they all go in and change that? 或者需要更改某些内容，他们不能都进去更改吗？ 12:19 PROFESSOR: So Hugo's raising the point, if you're down to, like, three nodes-- 教授：所以Hugo提出了一个观点，如果你只剩下大约三个节点—— 12:24 as I've shared with you all, the Australian Stock Exchange 正如我与大家分享的，澳大利亚证券交易所 12:29 is putting a permissioned blockchain 正在建立一个许可区块链 12:31 up using Digital Asset Holdings, which I think is backed by also 使用Digital Asset Holdings，我认为这也得到了 12:35 the Hyperledger Fabric technology. Hyperledger Fabric技术的支持。 12:38 But if it's just the Australian Stock Exchange, 但如果只是澳大利亚证券交易所， 12:41 and it's one node, or three nodes, couldn't they just change it on all three? 而且只有一个节点，或者三个节点，他们不能在所有三个节点上更改吗？ 12:46 And I think, in essence, yes. 我认为，本质上，是的。 12:48 I mean, that may not be what the database structure is, 我的意思是，这可能不是数据库结构的样子， 12:52 but I still think it's potentially yes. 但我仍然认为这可能是可以的。 12:57 So as you get more concentration, you have more chance. 所以随着集中度的增加，你有更多的机会。 13:01 But Brotish, I will try to research the Corda thing more specifically. 但Brotish，我会尝试更具体地研究Corda的事情。 13:06 Other thoughts? 其他想法？ 13:09 So then you create an auditable database-- some database with cryptography. 那么你就创建一个可审计的数据库——一个带有加密技术的数据库。 13:15 Hash functions, which half the class said they understood 哈希函数，班上有一半的人说他们理解 13:18 and the other half was sort of, you 而另一半则有点不太明白， 13:21 know, a little rough on, all is in permissioned systems, 你知道，有点粗糙，所有这些都在许可系统中， 13:29 using cryptographic schemes to ensure 使用加密方案来确保 13:33 for the validity of the data and, so to speak, the immutable nature of the data. 数据的有效性，以及可以说数据的不可变性。 13:39 What's different is consensus protocols. 不同的是共识协议。 13:43 In essence, it all goes down, except for Brotish's point, 本质上，所有这些都归结为，除了Brotish的观点， 13:46 maybe, about Corda, as to who gets the chance to add the additional data. 也许，关于Corda，谁有机会添加额外的数据。 13:53 Is it a small club deal, or is it broad, wide open? 这是一个小圈子的交易，还是广泛开放的？ 13:59 Everybody together, roughly? 大家一起，大致上？ 14:02 So back to the technical features. 那么回到技术特性。 14:04 Remember, it's a bunch of cryptography. 记住，这是一堆加密技术。 14:07 Love it or hate it, it actually allows us all 喜欢它或讨厌它，它实际上让我们所有人 14:11 to use the internet-- well past, obviously, 使用互联网——显然超越了 14:14 the blockchain that we're discussing in this class. 我们在这节课上讨论的区块链。 14:18 Network consensus, and then all the ledgers. 网络共识，然后是所有的账本。 14:22 So both permissioned and permissionless have ledgers, have cryptography. 因此，许可和无许可的都有账本，有加密技术。 14:28 It's that middle bucket that's different between the two. 这两个之间不同的是中间的那一部分。 14:33 So what were some of the challenges that we talked about in blockchain? 那么我们讨论的区块链的一些挑战是什么？ 14:40 We just talked about them 10 minutes ago, which is, what's the list again? 我们刚刚在10分钟前讨论过这些，那么列表是什么？ 14:44 See, this is the easy part. 看，这部分很简单。 14:45 If you haven't spoken yet, this is, like, the easy questions. 如果你还没有发言，这就像是简单的问题。 14:50 Oh, I'm hopelessly shameless. 哦，我真是无耻。 14:53 Yes. 是的。 14:55 Do you want to say your first name so Toledo takes you off the list? 你想说出你的名字，以便Toledo把你从名单上移除吗？ 14:59 AUDIENCE: [INAUDIBLE] PROFESSOR: Did you get it? 观众：[听不清] 教授：你听到了吗？ 15:02 No. 没有。 15:02 Do you want to say it louder? 你想大声说出来吗？ 15:04 Because Thalita [INAUDIBLE]. 因为Thalita [听不清]。 15:05 [INTERPOSING VOICES] [LAUGHTER] [交谈声] [笑声] 15:12 AUDIENCE: [INAUDIBLE] issue about the scalability. 观众：[听不清] 关于可扩展性的问题。 15:18 PROFESSOR: Scalability. 教授：可扩展性。 15:19 AUDIENCE: [INAUDIBLE] takes the time 观众：[听不清] 需要时间 15:21 to create the next block about [INAUDIBLE].. 来创建下一个区块关于[听不清]。 15:24 PROFESSOR: All right. 教授：好的。 15:25 So scalability and some time. 所以可扩展性和一些时间。 15:27 So efficiency and scalability. 所以效率和可扩展性。 15:29 Anything else? 还有其他吗？ 15:30 AUDIENCE: Privacy? 观众：隐私？ 15:31 PROFESSOR: Privacy. 教授：隐私。 15:35 So it's basically the scalability, 所以基本上可扩展性， 15:37 the privacy are two big things that permissioned systems address. 隐私是许可系统解决的两个重要问题。 15:44 Interoperability-- basically, how does this blockchain 互操作性——基本上，这个区块链如何 15:48 talk to other blockchains, or how does this blockchain 与其他区块链进行交互，或者这个区块链 15:51 talk to other legacy systems? 如何与其他传统系统进行交互？ 15:55 Permissioned and permissionless systems both have issues of interoperability. 许可和无许可系统都有互操作性的问题。 16:01 However, the smaller the club deal, 然而，俱乐部交易越小， 16:03 the more likely that a bank or the Australian Stock Exchange 银行或澳大利亚证券交易所更有可能 16:08 might address its interoperability right within 在系统内部解决其互操作性， 16:10 the system, whereas if it's a big open-sourced, open project-- 而如果是一个大型开源的开放项目—— 16:16 so IBM would say, we can even help you with interoperability. IBM会说，我们甚至可以帮助你解决互操作性问题。 16:21 IBM would say, we can help you with all four lines. IBM会说，我们可以帮助你解决所有四个方面。 16:24 We can help you with scalability, efficiency. 我们可以帮助你解决可扩展性和效率。 16:27 We can help you with privacy. 我们可以帮助你解决隐私问题。 16:29 We can help you with interoperability and governance. 我们可以帮助你解决互操作性和治理问题。 16:31 I think it's less clear they can help with all four, 我认为他们能帮助解决所有四个方面的可能性较小， 16:35 but they can certainly help with the first two. 但他们肯定可以帮助解决前两个问题。 16:39 And Alon, you've switched from using a permissionless 阿隆，你已经从使用无许可 16:43 to a permissioned system-- AUDIENCE: Correct. 转向了许可系统——观众：正确。 16:45 PROFESSOR: --in your startup, right? 教授：——在你的初创公司，对吗？ 16:48 Which of these four is the reason why you switched? 这四个中哪个是你转变的原因？ 16:51 AUDIENCE: So actually, I switched-- PROFESSOR: Or something else? 观众：所以实际上，我转变了——教授：还是其他原因？ 16:54 AUDIENCE: Something else. 观众：其他原因。 16:55 So for me, it was a business use case. 对我来说，这是一个商业用例。 16:57 So I was trying-- my business is selling to banks. 所以我在尝试——我的业务是向银行销售。 16:59 PROFESSOR: So that's the next line-- commercial use case. 教授：所以这是下一条——商业用例。 17:01 AUDIENCE: There it is. 观众：就是这样。 17:04 PROFESSOR: There's a setup. 教授：这是一个设置。 17:06 So what was the reason that you switched? 那么你转变的原因是什么？ 17:08 AUDIENCE: So I was building on Ethereum, which is public. 观众：所以我在以太坊上构建，它是公开的。 17:10 And I thought that it's unlikely that, in the near future, 我认为在不久的将来， 17:14 banks are going to adopt Ethereum as their underlying technology. 银行会采用以太坊作为其基础技术的可能性不大。 17:17 And then I learned about R3 and Corda, 然后我了解了R3和Corda， 17:20 and learned that banks actually funded that project. 并了解到银行实际上资助了该项目。 17:23 So I switched to where the banks put their money. 所以我转向了银行投资的地方。 17:26 PROFESSOR: So I would contend that it's a bit about interoperability. 教授：所以我认为这有点关于互操作性。 17:30 You felt your users would be more likely to be able to work with your system 你觉得你的用户更有可能与你的系统合作 17:37 if you were using Corda, with which they were familiar. 如果你使用的是他们熟悉的Corda。 17:41 AUDIENCE: Correct. 观众：正确。 17:42 So there's a business reason and technological reason. 所以有商业原因和技术原因。 17:45 PROFESSOR: And then, of course, there's the public policy reasons. 教授：当然，还有公共政策原因。 17:48 And IBM would even say that they're IBM甚至会说，他们 17:51 going to score higher points on the public policy 在公共政策上得分更高 17:55 if, for no other reason, that there's better privacy and security. 如果没有其他原因，那就是更好的隐私和安全。 17:59 Now, I'm not trying to shill for IBM. 现在，我并不是在为IBM做宣传。 18:02 I'm just saying these would be their selling points-- or Corda, or elsewhere. 我只是说这些将是他们的卖点——或者Corda，或者其他地方。 18:11 We talked about Buterin's trilemma. 我们谈到了布特林的三难困境。 18:13 But in another way, many people would 但从另一个角度来看，许多人会 18:16 say decentralization competes with scalability and security. 说去中心化与可扩展性和安全性相竞争。 18:21 If you want scalability and security, you can't have decentralization. 如果你想要可扩展性和安全性，就不能有去中心化。 18:26 I'm not a big believer in this trilemma, even though I've now raised it twice. 我并不是很相信这个三难困境，尽管我现在提到过两次。 18:31 But it's often talked about at blockchain conferences, 但它常常在区块链会议上被提及， 18:36 and blockchain papers, and business discussions. 以及区块链论文和商业讨论中。 18:39 So I've always told you I want to be a fair representation 所以我一直告诉你，我想要公正地代表 18:43 of the debate that's going on. 正在进行的辩论。 18:47 I think it's more possible to solve these three over time 我认为随着时间的推移，解决这三个问题的可能性更大 18:52 together than some others. 而不是其他一些问题。 18:55 But maybe I'm just a cockeyed optimist about technology. 但也许我只是对技术过于乐观。 19:02 So public policy framework. 所以公共政策框架。 19:04 What were the big three slipstreams? 三个主要的滑流是什么？ 19:05 So I went fast last time-- last class. 所以我上次讲得很快——上节课。 19:08 Leonardo, what are you going to tell me about the-- 莱昂纳多，你要告诉我关于—— 19:11 it's because you were adjusting your glasses. 这是因为你在调整眼镜。 19:14 AUDIENCE: Yeah. 观众：是的。 19:15 No, we spoke about the difficulty to implement framework. 不，我们谈到了实施框架的困难。 19:21 And you were talking more about the need [INAUDIBLE] 你在谈论更多关于需求的事情 [听不清] 19:26 offer security to protect people. 提供安全性以保护人们。 19:29 PROFESSOR: To protect people-- so it's sort of a privacy thing. 教授：保护人们——所以这有点像隐私问题。 19:32 I think I have a hand up here from Catalina. 我想这里有来自Catalina的举手。 19:37 AUDIENCE: There are three big things that [INAUDIBLE] public 观众：有三件大事 [听不清] 公共 19:41 policy working against illicit activity-- PROFESSOR: Illicit activity. 政策在打击非法活动——教授：非法活动。 19:48 AUDIENCE: --financial instability, and protecting the investors. 观众：——金融不稳定，以及保护投资者。 19:52 PROFESSOR: There you go. 教授：没错。 19:56 All right. 好的。 19:56 So you know my style. 所以你知道我的风格。 19:57 I try to drop things into three buckets. 我试着把事情分成三个类别。 20:00 But it's the only way I can remember anything. 但这是我记住任何事情的唯一方法。 20:03 But it is the three big buckets, of course. 当然，这就是三个大类别。 20:07 And since I went fast last time-- 上次我讲得很快—— 20:11 and we're going to be coming back to a lot of it, 而且我们将会回到很多内容， 20:13 but were there any questions that you have? 但你们有什么问题吗？ 20:15 And this is just an opportunity. 这只是一个机会。 20:16 Brotish? Brotish？ 20:17 AUDIENCE: So I have a question on the [INAUDIBLE] stability point. 观众：所以我有一个关于 [听不清] 稳定性的问题。 20:21 Like, you mentioned that because of the world 就像你提到的，因为全球 20:24 value of the digital currency is very minimal compared to, 数字货币的价值与 20:28 let's say, [INAUDIBLE]. 比如说， [听不清] 相比非常微小。 20:31 PROFESSOR: The value of crypto finance 教授：加密金融的价值 20:35 is about $220 billion right now, compared to worldwide capital 目前约为2200亿美元，相比全球资本 20:39 markets that, in aggregate, are over $300 trillion of debt, bonds, and equities. 市场总额超过300万亿美元的债务、债券和股票。 20:46 AUDIENCE: So my question was more like [INAUDIBLE] opinion 观众：所以我的问题更像是 [听不清] 意见 20:49 on this, that this value is also concentrated within a limited 关于这一点，这个价值也集中在有限的 20:53 number of people compared to the other assets that we are 人数相比于我们讨论的其他资产， 20:56 talking about, and hence-- I mean, it can still be important to regularize 因此——我的意思是，规范化仍然很重要 21:02 on the financial stability side, because it 在金融稳定方面，因为它 21:04 can have a effect which is not in proportion to just the size. 可能产生的影响与其规模不成比例。 21:08 PROFESSOR: So Brotish is asking the question that even 教授：所以Brotish在问，即使 21:10 though it's only $200 billion versus $300 虽然只有2000亿美元与300 21:14 plus trillion of worldwide financial assets, 万亿的全球金融资产相比， 21:19 couldn't it still be relevant to financial stability? 它仍然与金融稳定相关吗？ 21:23 And the answer is yes. 答案是肯定的。 21:26 But it's still relatively-- it's less than one one-thousandths 但它仍然相对较小——不到千分之一 21:29 of the broad size. 的整体规模。 21:31 AUDIENCE: [INAUDIBLE] PROFESSOR: Yes, please. 观众：[听不清] 教授：是的，请说。 21:34 Better you than me. 你比我好。 21:36 AUDIENCE: So basically, we did an analysis between 观众：所以基本上，我们做了一个分析 21:39 the correlation [INAUDIBLE] public market [INAUDIBLE] 相关性 [听不清] 公共市场 [听不清] 21:45 and basically there's a correlation of roughly 80% to 85% when the public-- 基本上，当公共市场—— 21:52 when the Bitcoin market's down, within the past year, 比特币市场下跌时，在过去一年中， 21:55 the public market's likely to lift up. 公共市场可能会上涨。 21:57 Because there's a lot of leverage built into the system. 因为系统中有很多杠杆。 22:00 And once the volatility kicks in, a lot of the investors [INAUDIBLE] 一旦波动性开始，很多投资者 [听不清] 22:06 they have to get money out from the public market, 他们必须从公共市场中撤出资金， 22:08 and that kind of feeds into a loop. 这就形成了一个循环。 22:10 PROFESSOR: So you're saying there's correlation, 教授：所以你是说有相关性， 22:12 and there may be feedback loops. 并且可能存在反馈循环。 22:15 Tom? 汤姆？ 22:16 AUDIENCE: Sort of a related question. 观众：有一个相关的问题。 22:17 So Mervyn King was in this room a couple hours ago, 几小时前，Mervyn King在这个房间里， 22:20 and he was talking about, in the '08 crisis, 他在谈论08年危机时， 22:23 two issues of trust-- one where there was a counterparty trust issue. 信任的两个问题——一个是存在对手方信任问题。 22:28 Even though the overall derivatives market 尽管整体衍生品市场 22:30 was [INAUDIBLE],, banks didn't individually 是 [听不清]，银行并不知道 22:34 know which other bank was most at risk. 哪家银行面临的风险最大。 22:36 And so they wouldn't trade with each other or lend to one another. 因此，他们不会相互交易或借贷。 22:40 And then on the opposite side, the solution-- 然后在另一边，解决方案—— 22:43 the salvation-- was two people in a room trusting 拯救——是两个在房间里的人相互信任 22:47 each other that the central bank-- that the government 彼此相信中央银行——政府 22:49 would fund tens of billions of dollars [INAUDIBLE] capital. 会提供数十亿美元的 [听不清] 资本。 22:53 And so I wonder your thoughts on blockchain's role 所以我想知道你对区块链在 22:58 in addressing that first problem of knowing your counterparty, or at least being 解决第一个问题——了解你的对手方，或者至少是 23:02 able to trust their position, and then the risk 能够信任他们的位置，然后风险 23:05 of eliminating the second chance of injection of capital 消除资本注入的第二次机会的风险 23:09 into the financial system in a blockchain. 在区块链的金融系统中。 23:13 PROFESSOR: Russ, [INAUDIBLE]. 教授：拉斯，[听不清]。 23:14 AUDIENCE: I had a question. 观众：我有一个问题。 23:16 It's related to this-- PROFESSOR: All right. 观众：这与此相关——教授：好的。 23:17 AUDIENCE: --which is-- PROFESSOR: Thanks, Brotish. 观众：——这是——教授：谢谢，布罗提什。 23:19 [INAUDIBLE] AUDIENCE: But the question is this. [听不清]观众：但问题是这样的。 23:22 It does strike me that you only have a financial stability 我觉得只有在金融稳定性方面 23:25 problem if people are relying on the value of people's 问题，如果人们依赖于人们的价值 23:32 Bitcoin holdings, for example, which is the bulk of crypto assets, right? 比特币持有量，例如，这就是大部分加密资产，对吧？ 23:37 The reason you have the problem during the crisis is you have all these banks. 你在危机期间遇到问题的原因是你有这些银行。 23:41 They're carrying these assets on their balance sheet. 他们在资产负债表上持有这些资产。 23:43 And all of the sudden, people think they don't know what they're worth, right? 突然之间，人们认为他们不知道这些资产的价值，对吧？ 23:47 Who, if anyone, is actually carrying a Bitcoin assets 谁，如果有的话，实际上在持有比特币资产 23:51 on a balance sheet that someone else is relying on? 在一个别人依赖的资产负债表上？ 23:54 Or, to put it differently, who's extending the leverage? 或者换句话说，谁在扩展杠杆？ 23:56 PROFESSOR: All right. 教授：好的。 23:57 So let me-- AUDIENCE: [INAUDIBLE] PROFESSOR: Let me wrap these together. 所以让我——观众：[听不清]教授：让我把这些结合起来。 24:01 I think that what many central bankers and the Financial 我认为许多中央银行家和金融 24:05 Stability Board would say, at 200 billion 稳定委员会会说，2000亿 24:08 versus 300 trillion, it's probably not that financially relevant at this point. 与300万亿相比，目前可能并不是那么财务相关。 24:16 Where it could get relevant is, as Russ has sort of suggested, 它可能变得相关的地方是，正如拉斯所暗示的， 24:21 is if there's leverage behind it. 如果它背后有杠杆。 24:23 If it's in a balance sheet, it's an asset on a balance sheet, 如果它在资产负债表上，它就是资产， 24:26 and there's a liability on the other side. 而另一边则有负债。 24:28 And thus it could bring down that entity, 因此，它可能会使该实体崩溃， 24:31 whether it's a hedge fund, whether it's a bank. 无论是对冲基金，还是银行。 24:35 But something that's relying [INAUDIBLE] to tie it 但有些依赖[听不清]的东西将其联系起来 24:40 back to the questions that Tom raised is, could blockchain lower systemic risk? 回到汤姆提出的问题，区块链能否降低系统性风险？ 24:48 Possibly, if it's a better database solution. 可能，如果它是更好的数据库解决方案。 24:53 If it answers-- what Mervyn King was speaking about, 如果它回答了——梅尔文·金所说的， 24:56 we also addressed in the late 90s. 我们在90年代末也讨论过。 24:59 I remember quite well when Secretary Rubin 我记得很清楚，当时鲁宾部长 25:02 called a number of us into his office and said, I don't understand. 召集我们几个人到他的办公室，说，我不明白。 25:05 The banks can't tell us their exposure to Korea. 银行无法告诉我们他们对韩国的风险敞口。 25:08 A number of countries-- South Korea was about to have-- but they 一些国家——韩国即将发生——但他们 25:12 didn't default on their debt, but they 并没有违约，但他们 25:14 were coming close to defaulting on their debt. 接近违约。 25:17 And of course, it was only a short while 当然，仅仅过了一段时间 25:19 before other countries, like Indonesia and Thailand, 其他国家，如印度尼西亚和泰国， 25:22 were getting into that same debt challenge. 也面临同样的债务挑战。 25:27 But why couldn't banks tell the US Department of Treasury their exposure? 但为什么银行无法告诉美国财政部他们的风险敞口？ 25:31 It's usually through derivatives. 通常是通过衍生品。 25:35 And derivatives, both in the late '90s and the financial crisis, were often 而衍生品，无论是在90年代末还是金融危机中，通常 25:41 something that propagated risk through the system. 是通过系统传播风险的东西。 25:45 Now, the numbers were larger-- I mean, depending upon the time. 现在，数字更大——我的意思是，取决于时间。 25:49 The '90s was less than this. 90年代的数字少于这个。 25:51 But it was $300, $400 trillion of notional amount of derivatives. 但它是300万亿、400万亿的名义衍生品金额。 25:56 So just the sheer notional size, even though the capital at risk in derivatives 所以仅仅是名义规模，尽管衍生品的风险资本 26:01 was much smaller because the leverage of this notional-- big, notional size. 要小得多，因为这个名义的杠杆——大的名义规模。 26:08 And the transparency was pretty low. 而透明度非常低。 26:11 It wasn't zero, actually. 实际上并不是零。 26:13 It wasn't zero. 并不是零。 26:14 But it was really low. 但它确实很低。 26:17 And so I think that's what Mervyn King would have been mentioning. 所以我认为这就是梅尔文·金所提到的。 26:22 And I do think blockchain can help in that transparency. 我确实认为区块链可以帮助提高透明度。 26:26 But it takes a big collective action. 但这需要大规模的集体行动。 26:28 And so Europe, the US, and Asia-- a lot of laws 因此，欧洲、美国和亚洲——许多法律 26:31 were passed to get more transparency in the derivatives space. 被通过以获得衍生品领域的更多透明度。 26:36 Brotish, I would say that there could be problems. 布罗提什，我想说可能会有问题。 26:39 And I've had conversations with elected leaders that 我与一些当选领导人进行了交谈，他们 26:42 say, don't get lulled into the sense 说，不要被这种感觉迷惑 26:45 that it won't have financial stability issues. 认为这不会有金融稳定性问题。 26:49 Because that was what happened in the 1980s and '90s 因为这就是1980年代和1990年代发生的事情。 26:52 when people said, well, derivatives will not 当人们说，衍生品不会 26:55 create instability, because it's only 造成不稳定，因为这只是 27:01 the institutional investors, the sophisticated investors-- 机构投资者，成熟的投资者-- 27:05 the so to speak big boys or big girls, you know? 所谓的大人物，你知道吗？ 27:10 And I was part of those debates, that consensus that formed that 我参与了那些辩论，形成了这样的共识 27:16 it was only institutional and it wouldn't-- 这只是机构投资者，不会-- 27:19 but there was a lot of leverage and a lack of transparency when big leverage-- 但当大杠杆存在时，杠杆很大且缺乏透明度-- 27:24 multiple hundreds of trillions of dollars-- 数以百计的万亿美金-- 27:26 associated with it, of course, was part of the crisis-- 与之相关的，当然是危机的一部分-- 27:31 not the only part of the crisis. 不是危机的唯一部分。 27:32 But any other questions before Hugo? 在Hugo之前还有其他问题吗？ 27:35 AUDIENCE: Yeah. 观众：有。 27:36 On the protecting the investing public front, 关于保护投资公众这一方面， 27:38 I was just wondering, like, a lot of people 我只是想知道，很多人 27:42 are now using Robinhood and zero fee things like that 现在都在使用Robinhood和零费用的东西 27:45 to invest in the stock market. 来投资股市。 27:48 And companies like Robinhood and Vanguard 像Robinhood和Vanguard这样的公司 27:51 often sell order book data to high frequency traders 通常会将订单簿数据出售给高频交易者 27:55 so that they can kind of know what's going on and maybe front run. 以便他们可以了解情况并可能进行前置交易。 28:00 So I was wondering how that fits into what we were talking about last time where 所以我想知道这与我们上次讨论的内容如何契合， 28:07 there's no transparency on many of the cryptocurrency exchanges. 许多加密货币交易所缺乏透明度。 28:12 And then in addition to that, big institutional investors 此外，大型机构投资者 28:17 can, I think, buy upwards of 5% of any stock 可以，我认为，可以购买任何股票超过5% 28:22 and then wait a few days before they have to report on that. 然后等几天再报告。 28:28 So that can also have a huge effect on stock price. 这也会对股价产生巨大影响。 28:31 And then they can, afterwards, dump on people. 然后他们可以在之后抛售给别人。 28:35 So how is that different from what's going on in cryptocurrency exchanges? 那么这与加密货币交易所发生的情况有什么不同？ 28:40 PROFESSOR: All right. 教授：好的。 28:40 So that's an investor protection one. 这是一个投资者保护的问题。 28:41 Was there another one in the-- is this investor protection, or-- 还有其他问题吗--这是投资者保护，还是-- 28:45 AUDIENCE: No, it's a little bit different. 观众：不，这有点不同。 28:46 PROFESSOR: A little different. 教授：有点不同。 28:47 All right. 好的。 28:48 Any other investor protection? 还有其他投资者保护的问题吗？ 28:49 Because I'm going to collect them and then [INAUDIBLE].. 因为我会收集它们，然后[听不清].. 28:50 AUDIENCE: It's about the former. 观众：这是关于前者的。 28:52 I was a little bit-- 我有点-- 28:53 it was kind of [INAUDIBLE] to me when you say the blockchain can 当你说区块链可以时，我有点[听不清] 28:58 help to stabilize the financial markets-- PROFESSOR: All right. 帮助稳定金融市场--教授：好的。 29:00 So that's back to financial stability. 所以这又回到了金融稳定。 29:01 AUDIENCE: Yeah. 观众：是的。 29:02 If it can-- PROFESSOR: All right. 如果可以的话--教授：好的。 29:03 Can I hold it? 我可以拿着吗？ 29:03 Let me just answer Hugo's investor protection one. 让我来回答Hugo的投资者保护问题。 29:07 So all markets-- not just crypto markets-- 所以所有市场--不仅仅是加密市场-- 29:13 all markets are susceptible to some forms of front running. 所有市场都容易受到某些形式的前置交易影响。 29:17 In essence, if you have a client relationship 本质上，如果你有客户关系 29:21 and you get information from your client that 并且你从客户那里获得信息 29:24 might affect the market pricing, you 可能会影响市场定价，你 29:28 might jump ahead of that client with their information. 可能会利用他们的信息抢先于客户。 29:32 Their information might be a buy order, a sell order. 他们的信息可能是买单或卖单。 29:36 Or frankly, it might be some other information. 坦率地说，这可能是其他信息。 29:38 But traditionally, if they have a buy order or a sell order, 但传统上，如果他们有买单或卖单， 29:42 you have information. 你就有信息。 29:43 And then you're sort of jumping ahead and saying, all right. 然后你就会抢先一步，说，好吧。 29:49 I'll buy or sell in front of them. 我会在他们面前买入或卖出。 29:51 That's the classic sort of front running, even though there's other methods. 这就是经典的前置交易，尽管还有其他方法。 29:57 It's not supposed to happen. 这不应该发生。 29:59 On regulated exchanges, you have some policing of it. 在受监管的交易所，你会有一些监管。 30:04 Even before governments stood in, you could have some policing of it 即使在政府介入之前，你也可以进行一些监管 30:08 in self-regulatory organizations. 在自律组织中。 30:11 In the crypto world, there is Katy bar the door. 在加密世界中，几乎没有限制。 30:16 Anything can really happen. 任何事情都可能发生。 30:18 And it's my belief and understanding 我相信并理解 30:21 that many crypto exchanges-- not all of them. 许多加密交易所--并不是所有的。 30:24 Not all of them. 并不是所有的。 30:25 But many crypto exchanges are basically trading in front of their customers. 但许多加密交易所基本上是在客户面前进行交易。 30:32 And in fact, most crypto exchanges 实际上，大多数加密交易所 30:35 make markets, as they are both market makers-- 作为市场制造者，他们创造市场—— 30:39 meaning they are buying when you're selling and selling when you're buying. 这意味着他们在你卖出时买入，在你买入时卖出。 30:43 That's the nature of a market maker. 这就是市场制造者的本质。 30:45 It's very typical, very legal, very important function of market. 这是市场中非常典型、合法且重要的功能。 30:49 But the exchanges are both market makers, and then they show order books. 但交易所也是市场制造者，然后他们展示订单簿。 30:54 And so it sort of helps them do front running. 因此，这在某种程度上帮助他们进行前跑。 31:00 Not that a lot of people necessarily agree with me, 并不是很多人一定同意我的看法， 31:03 I think these markets would be better off 我认为这些市场会更好， 31:05 if there were some forms of rules about front running 如果有一些关于前跑的规则， 31:08 and manipulation in markets and the like. 以及市场操纵等方面的规则。 31:11 On your 5% question, can we take it up in office hours or something? 关于你的5%问题，我们可以在办公时间讨论一下吗？ 31:14 Because it's sort of outside of crypto. 因为这有点超出了加密货币的范围。 31:16 But I would be glad to talk about the SEC rules about the 5%. 但我很乐意讨论关于5%的SEC规则。 31:21 Is this investor protection? 这是否是投资者保护？ 31:22 And that-- AUDIENCE: I think so. 那——观众：我认为是的。 31:24 The reading that we had that talked about the Fabric 我们阅读的关于Fabric的材料提到， 31:27 technology, it mentioned something about execute order validate. 技术中提到了一些关于执行订单验证的内容。 31:31 Does that mechanism tie into the way that front running would work at all? 这个机制是否与前跑的工作方式有关？ 31:36 PROFESSOR: All blockchain technology, 教授：所有区块链技术， 31:38 whether it's permissioned, like Fabric, or permissionless, can-- 无论是许可的（如Fabric）还是无许可的，都可以—— 31:44 if it was efficient and scalable-- 如果它是高效且可扩展的—— 31:47 could help out, because you could actually timestamp when did the order come in. 可以提供帮助，因为你可以实际记录订单何时到达。 31:53 When did the client's information 客户的信息何时到达 31:56 get to the exchange, and is somebody standing in front? 交易所，以及是否有人在前面？ 32:00 AUDIENCE: So it's sort of like a cascade 观众：所以这有点像级联， 32:01 that you can't necessarily pause once it starts? 一旦开始就无法暂停？ 32:05 PROFESSOR: Right, right. 教授：对，对。 32:06 So if you look at the algorithms at the New York Stock Exchange 所以如果你看看纽约证券交易所的算法， 32:10 right now, which are not blockchain-- they're not permissioned, and they're not 现在，它们不是区块链——它们不是许可的，也不是 32:15 permissionless blockchain. 无许可的区块链。 32:16 But if you look at both the algorithms and the data flows, 但如果你查看算法和数据流， 32:19 they have very good timestamping. 它们有非常好的时间戳记录。 32:22 I'm not going to say it's perfect, but they have very good timestamping 我不会说它是完美的，但他们有非常好的时间戳记录 32:24 to ensure when are orders-- 以确保订单的时间—— 32:28 basically message timestamping every message that comes in. 基本上是对每条消息进行时间戳记录。 32:32 And some order books, like the New York Stock Exchange-- 一些订单簿，如纽约证券交易所—— 32:36 some order books are price and time priority, 一些订单簿是价格和时间优先， 32:41 price priority meaning high bid gets hit before the next bid, 价格优先意味着高出价在下一个出价之前被击中， 32:45 or lowest offer gets lifted first. 或最低报价首先被接受。 32:49 That's price priority. 这就是价格优先。 32:51 But they might also have time priority 但他们也可能有时间优先 32:53 for any bid that has the same price and any offer that's the same price. 对于任何具有相同价格的出价和任何相同价格的报价。 32:59 So they have to have very good timestamping. 所以他们必须有非常好的时间戳记录。 33:05 I truly believe you could not use a blockchain 我真的相信你不能使用区块链 33:08 solution for the New York Stock Exchange order book right now. 解决方案来处理纽约证券交易所的订单簿。 33:12 Whether you can in 10 years, I'm not sure. 在10年内是否可以，我不确定。 33:15 But time latency is so relevant in the middle of those order books-- 但时间延迟在这些订单簿中是如此重要—— 33:20 you know, the nanoseconds that matter. 你知道，纳秒是重要的。 33:22 I'm going to take this stability question. 我将回答这个稳定性问题。 33:24 There were two stability-- and then 有两个稳定性——然后 33:26 we're going to move on to the rest of today's lecture. 我们将继续今天讲座的其余部分。 33:30 You're having fun now. 你们现在玩得很开心。 33:31 AUDIENCE: Can you explain a little bit more about, like, well, say if blockchain 观众：你能多解释一下，比如说，如果区块链 33:37 can be a better database so it can help stabilize the financial market? 可以成为更好的数据库，以帮助稳定金融市场吗？ 33:42 Can you give some examples? 你能给一些例子吗？ 33:44 PROFESSOR: So how blockchain could possibly help-- be a stabilizer. 教授：那么区块链可能如何帮助——成为一个稳定器。 33:49 A lot of financial instability-- or, beyond the financial markets, 许多金融不稳定——或者，超越金融市场， 33:54 instability is a question of resilience. 不稳定是一个韧性的问题。 33:57 And when things are centralized, you 当事物集中时，你 34:00 create single points of failure in any system-- 在任何系统中创建单点故障—— 34:04 really, in military or financial. 实际上，无论是在军事还是金融领域。 34:08 You centralize something, you then, thus-- you know what to attack. 你集中某样东西，那么，你知道该攻击什么。 34:14 You can also maybe have higher walls or better moats, 你也可以有更高的墙或更好的护城河， 34:17 but you still know of something to attack. 但你仍然知道有什么可以攻击的。 34:20 So blockchain, in its decentralized nature, might be a more resilient database, 因此，区块链在其去中心化的特性中，可能是一个更具韧性的数据库， 34:26 because even if half or two thirds of it goes down, 因为即使一半或三分之二的部分出现故障， 34:29 you still have the other third. 你仍然有另外三分之一。 34:30 I'm going to say something about the New York Stock Exchange again. 我想再说一下纽约证券交易所。 34:33 Whether it's the New York Stock Exchange, the London Stock 无论是纽约证券交易所、伦敦证券交易所， 34:35 Exchange, the Chicago Mercantile Exchange, 芝加哥商品交易所， 34:37 they all are required by their various local laws to have backup data centers. 它们都被各自的地方法律要求必须拥有备份数据中心。 34:47 And those backup data centers even have to be lots of miles 而这些备份数据中心甚至必须距离主中心几英里远， 34:52 away if, God forbid, a bomb comes and takes out the center. 以防万一，发生炸弹袭击摧毁主中心。 34:57 AUDIENCE: [INAUDIBLE] PROFESSOR: What's that? 观众：[听不清] 教授：那是什么？ 35:00 It's called-- Its basically disaster recovery. 这被称为——基本上是灾难恢复。 35:02 So maybe blockchain will be more resilient. 所以也许区块链会更具弹性。 35:05 I'm going to take two more questions and then get back to permissioned 我将再接受两个问题，然后回到许可与非许可的讨论。 35:08 versus permissionless. 与非许可。 35:09 Way back in the corner-- your first name, again, is? 在角落里——你的名字是什么？ 35:12 AUDIENCE: Matt. 观众：马特。 35:12 PROFESSOR: Matt. 教授：马特。 35:13 Thank you, Matt. 谢谢你，马特。 35:14 I should know that. 我应该知道的。 35:15 AUDIENCE: So I'm kind of just curious how, essentially, the nasency, 观众：所以我有点好奇，基本上，这个新兴市场， 35:18 for lack of a better word-- PROFESSOR: The [INAUDIBLE]? 缺乏更好的词汇——教授：[听不清]？ 35:21 AUDIENCE: Like, the nasency-- how kind of, like, new this market 观众：就像，这个新兴市场——这个市场有多新， 35:25 is and how that affects policy, because when you're shaping 以及这如何影响政策，因为当你在制定政策时， 35:29 policy, and you don't necessarily 你不一定有很多年的经验来了解人们如何 35:32 have a bunch of years of knowing how people are going 反应这些政策，我觉得这几乎可以说是一个鸡和蛋的情况。 35:35 to react to that policy, I feel like it could almost 35:38 be a chicken and egg situation. 35:39 PROFESSOR: OK, I understand. 教授：好的，我明白了。 35:40 Anybody else with the same theme? 还有其他人有同样主题的问题吗？ 35:43 No? 没有吗？ 35:43 So the question is, how does it affect policy makers 所以问题是，当一项技术是新的时，它如何影响政策制定者？ 35:47 when a whole technology is new? 35:50 And I would say, we have a lot of history with this. 我想说，我们在这方面有很多历史。 35:55 Whether it was railroads, or the telegraph, 无论是铁路、还是电报， 35:58 or the telephone, or television, we have a lot of history. 还是电话、还是电视，我们都有很多历史。 36:04 Technology and commercial applications move ahead of the public sector. 技术和商业应用总是走在公共部门之前。 36:11 I mean, it's just inevitable. 这几乎是不可避免的。 36:14 The official sector, the public sector-- 官方部门，公共部门—— 36:16 unless it just basically does what Mark Carney says, 除非它基本上按照马克·卡尼所说的去做， 36:19 and the choice is to isolate something, to sort of put up 否则选择就是隔离某些东西，建立起 36:22 the moats of a society and says, we can't use that technology here. 社会的护城河，并说，我们不能在这里使用那项技术。 36:27 Unless you have that, technology usually supersedes the markets, 除非你有那样的情况，技术通常会超越市场， 36:32 and the markets and technology come before official sector. 市场和技术总是先于官方部门。 36:36 Depending upon the area, it can take 根据不同领域，公共部门可能需要 36:39 single digit years and sometimes decades for public sector 几年的时间，有时甚至几十年才能赶上， 36:43 to catch up, literally. 字面上来说。 36:46 But let's take the internet. 但我们来谈谈互联网。 36:48 The internet was being worked on for 15ish years. 互联网的开发持续了大约15年。 36:53 But the protocol layer that helped take off 但帮助其发展的协议层是在1991年或1992年的万维网， 36:57 was the worldwide web in 1991 or '92, and then the security protocols in '96. 以及1996年的安全协议。 37:05 Just taking financial regulation, 以金融监管为例， 37:07 the SEC was asked in 1995, could bulletin boards-- 1995年，SEC被问到，电子公告板是否可以—— 37:16 there were electronic bulletin boards listing stocks and bonds-- 有电子公告板列出股票和债券—— 37:20 be exempted from being considered stock exchanges? 是否可以免于被视为证券交易所？ 37:25 Well, the people that were asking that 提出这个问题的人 37:27 were the people putting up the bulletin boards. 正是那些建立公告板的人。 37:29 They didn't want to be regulated. 他们不想受到监管。 37:32 The New York Stock Exchange that was fully regulated, 完全受监管的纽约证券交易所， 37:35 and NASDAQ that was fully regulated, was coming at the other side and asking 以及完全受监管的纳斯达克，正从另一边要求 37:39 the SEC to shut them down. SEC关闭这些公告板。 37:41 They didn't want the competition from the disruptors. 他们不想与这些颠覆者竞争。 37:44 It took three years for the SEC to answer that question. SEC花了三年时间来回答这个问题。 37:49 I don't mean answer it, like, with a letter. 我不是说用一封信来回答。 37:52 They had to propose a rule, and they had to do a final rule, 他们必须提出一项规则，并制定最终规则， 37:55 and it was three years to do that. 而这花了三年的时间。 37:59 And blockchain, I think, we are through some of the big questions. 而我认为，区块链方面我们已经解决了一些重大问题。 38:06 We know how most jurisdictions tax-- 我们知道大多数司法管辖区如何征税—— 38:09 T-A-X-- tax it as property and not as currency, and some of the tax issues. 将其视为财产而不是货币，以及一些税务问题。 38:14 We know, in most jurisdictions, how it fits into, broadly, Bank Secrecy 我们知道，在大多数法域中，它大致上如何适应银行保密法 38:19 Act and illicit activity. 以及非法活动。 38:23 There's very choppy implementation, very spotty implementation. 实施非常不稳定，情况非常零散。 38:27 I would say the investor protection side, we're at the early stages. 我认为在投资者保护方面，我们还处于早期阶段。 38:31 And it's going to take, in most jurisdictions, another three 在大多数法域中，这可能还需要三年 38:34 years, maybe, to sort through some of how-- and this is just crypto finance. 来理清一些事情——这仅仅是加密金融。 38:40 I don't know. 我不知道。 38:40 Matt, does that-- I'm giving you some predictions. 马特，这样说，你觉得怎么样——我给你一些预测。 38:44 Some of it could be multiple decades. 其中一些可能需要几十年。 38:46 We're still, today, trying to figure out-- 我们今天仍在努力弄清楚—— 38:48 the public sector's figuring out how to regulate Facebook and Google. 公共部门正在弄清楚如何监管Facebook和Google。 38:52 I'm going to take one last question, because I've got to do permissioned. 我将接受最后一个问题，因为我必须处理许可问题。 38:55 AUDIENCE: [INAUDIBLE] because I was kind of, like-- 观众：[听不清]因为我有点像—— 38:58 it kind of answers the side following the technology. 这在某种程度上回答了跟随技术的一方。 39:01 But I think, for me, what I was kind 但我认为，对我来说，我想知道的是， 39:02 of wondering about was this, the way we're like-- as soon as you 我想知道的是，当我们——一旦你 39:05 apply regulations to something that at least a good portion 对某些东西施加监管，而至少市场的一部分 39:08 of the market seems to value being deregulated, 似乎重视去监管， 39:12 it seems like a lot of the activity will change, either in scope or scale. 似乎很多活动会改变，无论是在范围还是规模上。 39:15 PROFESSOR: So Matt's raising there's a trade-off about bringing something 教授：所以马特提到，关于将某些东西纳入监管的权衡 39:20 under regulation or into the public policy sphere. 或进入公共政策领域。 39:27 I'm probably just one voice of this, but I think it's probably true. 我可能只是这个观点中的一个声音，但我认为这可能是正确的。 39:31 There's very few economic activities 几乎没有经济活动 39:33 that grow large that stay fully outside of the public policy 能够快速增长而完全不受公共政策 39:38 framework of a society. 框架约束的社会。 39:41 It doesn't mean that public policy frameworks don't change, 这并不意味着公共政策框架不会改变， 39:44 get adopted, get adapted. 被采纳，得到调整。 39:46 The internet comes along, and at first, it's 互联网的出现，起初是 39:48 a question of-- you know, with Amazon, is it going to be taxed or not? 一个问题——你知道，关于亚马逊，它会被征税吗？ 39:52 Is there sales tax? 是否有销售税？ 39:53 And then later-- you know, at first, it's not. 然后后来——你知道，起初是没有的。 39:56 Later, it is. 后来是有的。 39:57 And in some jurisdictions, questions on the internet was liability. 在某些法域中，互联网的问题是责任。 40:02 And this was a very critical question of early internet was, 这是早期互联网的一个非常关键的问题， 40:06 was there liability for any of the information or the flow of information? 是否对任何信息或信息流承担责任？ 40:12 I'm talking about libel laws and all the liability issues and so forth. 我说的是诽谤法和所有责任问题等等。 40:17 And so in the US, there's a section of the law in 1996 was passed. 因此，在美国，1996年通过了一项法律条款。 40:23 And now we're coming back and saying, wait a minute. 现在我们回过头来说，等一下。 40:25 That gave too broad-- it basically exempted the internet 这给予了过于宽泛的——它基本上使互联网免于 40:29 from liability as carriers. 作为承载者的责任。 40:32 But now, that was modified in 2018-- 但现在，这在2018年被修改—— 40:36 22 years later-- to say, well, if it has to do, I think, 22年后——就是说，如果涉及到，我认为， 40:40 with basically children trafficking and slavery 基本上与儿童贩卖和奴隶制有关， 40:44 and everything, maybe we should tighten that up a little bit. 以及其他一切，也许我们应该稍微收紧一下。 40:50 So I don't believe any broad economic activity 所以我不相信任何广泛的经济活动 40:57 is going to remain fully outside public policy frameworks. 会完全不受公共政策框架的约束。 41:04 And I'm glad to be challenged on that. 我很高兴能对此提出挑战。 41:08 And I think blockchain, and particularly crypto finance, 我认为区块链，特别是加密金融， 41:11 is at this grappling stage to get in. 正处于进入这一阶段的挣扎中。 41:13 So let me move forward, because this 所以让我继续，因为这 41:15 is more about permissioned and permissionless. 更多的是关于许可和无许可。 41:17 I just wanted to cover some of these. 我只是想涵盖其中的一些内容。 41:19 We will cover initial coin offerings and the public policy 我们将讨论首次代币发行和公共政策 41:22 issues around initial coin offerings in the Howey Test. 在Howey测试中围绕首次代币发行的问题。 41:24 We will cover crypto exchanges, and we 我们将讨论加密交易所，以及我们 41:26 will cover central bank digital currencies a lot 将大量讨论中央银行数字货币 41:30 in the second half of this semester. 在本学期的下半部分。 41:34 So back to the trade-offs that we talked about already-- 所以回到我们已经讨论过的权衡—— 41:38 the trade-offs of centralization and decentralizations 集中化和去中心化的权衡 41:41 and Coase's work from the 1930s about the firm. 以及科斯在1930年代关于公司的研究。 41:46 This is the cost, remember. 这是成本，记住。 41:47 This is the cost. 这是成本。 41:48 As we get centralized, there's more cost of economic rents, 随着我们变得集中化，经济租金的成本增加， 41:52 single points of failure, and capture. 单点故障和控制。 41:56 Some fragility, in a sense, in the system. 在某种意义上，系统中存在一些脆弱性。 41:59 But decentralization has its cost as well. 但去中心化也有其成本。 42:03 You'll notice that these two lines are crossing somewhere. 你会注意到这两条线在某个地方交叉。 42:07 It was my failed attempt to say, you know, maybe there's a balance. 这是我失败的尝试，想说，也许存在一种平衡。 42:12 Maybe overall, while some organizations 也许总体来说，虽然一些组织 42:16 will find all the way to decentralization, and some to centralization, I think 会找到完全去中心化的道路，而一些则走向中心化，我认为 42:20 economic systems tend more towards the centralized side of things. 经济系统更倾向于中心化的一面。 42:26 But you can change the slope of these two lines if you want. 但如果你愿意，你可以改变这两条线的斜率。 42:30 I'm just trying to give you a framework of thinking about it. 我只是想给你一个思考的框架。 42:36 So as we've talked about, the financial sector 正如我们所讨论的，金融行业 42:39 pretty much favors permissioned systems. 基本上偏向于许可系统。 42:42 The financial sector is saying, going back, no. 金融行业在说，回去吧，不。 42:47 Too many costs of coordination, governance, security, privacy, and scalability. 协调、治理、安全、隐私和可扩展性的成本太高。 42:54 We're over in the other side. 我们在另一边。 42:58 And so that's where they are today. 所以这就是他们今天所处的地方。 43:02 I'm not sure that's where they'll be in five or 10 years, 我不确定他们在五年或十年后会在哪里， 43:05 but it is definitely where they are today. 但这绝对是他们今天所处的地方。 43:09 So let's go back down our list, in a sense. 所以在某种意义上，让我们回到我们的列表中。 43:13 I'm going to have a bunch of check marks and x's on the right. 我将在右侧有一堆勾号和叉号。 43:16 Where do you think I'm going to have check marks and x's? 你认为我会在哪里有勾号和叉号？ 43:20 This is the same three big buckets, because I can't think of anything. 这是同样的三个大类，因为我想不出其他东西。 43:24 Emily, do you have a point of view? 艾米莉，你有什么看法？ 43:27 AUDIENCE: I mean, I think in terms 观众：我的意思是，我认为在 43:29 of the permissioned technical features, one of them 许可技术特征方面，其中之一 43:32 is obviously that it's not using that proof of work. 显然是它没有使用工作量证明。 43:36 PROFESSOR: Not using-- AUDIENCE: It's not using the same proof of work. 教授：不使用——观众：它没有使用相同的工作量证明。 43:38 PROFESSOR: Not using proof of work. 教授：不使用工作量证明。 43:39 So I had to give away-- you know, reveal the [INAUDIBLE].. 所以我不得不透露——你知道，揭示[不可理解]。 43:45 All the cryptography that's used in permissionless systems 在无许可系统中使用的所有密码学 43:51 is used in the permissioned systems. 也在许可系统中使用。 43:53 It might be used a little differently. 它可能会以稍微不同的方式使用。 43:55 I'm not going to say the Merkle trees are exactly the same. 我不会说Merkle树完全相同。 43:59 But all that broccoli we were eating a few lectures ago 但我们几节课前吃的所有西兰花 44:02 are relevant on both sides. 在两边都是相关的。 44:07 Sorry, Alin. 抱歉，阿林。 44:09 AUDIENCE: [INAUDIBLE] PROFESSOR: What's that? 观众：[不可理解] 教授：那是什么？ 44:10 You-- AUDIENCE: I like broccoli. 你——观众：我喜欢西兰花。 44:11 PROFESSOR: You like broccoli. 教授：你喜欢西兰花。 44:13 A computer scientist speaking. 一位计算机科学家在发言。 44:15 Everything, though, about digital signatures and hash 不过，关于数字签名和哈希的所有内容 44:18 functions and so forth are relevant to both of these. 函数等在这两者中都是相关的。 44:22 But they're not necessarily relevant to every traditional database, which we'll 但它们不一定与每个传统数据库相关，我们将在 44:27 talk about in 10 minutes or so. 大约10分钟后讨论。 44:31 But as Emily said, there's really not-- I said, no. 但正如艾米莉所说，实际上没有——我说，没有。 44:35 There's not decentralized network consensus. 没有去中心化的网络共识。 44:38 I'm stretching it a little bit, because permissioned systems 我有点牵强，因为许可系统 44:41 can be decentralized. 可以是去中心化的。 44:42 There could be five or 10 or 20 nodes. 可能有五个、十个或二十个节点。 44:46 And so that is decentralized. 所以这就是去中心化的。 44:48 So I shouldn't have really said no. 所以我真的不应该说没有。 44:51 I should have said maybe, or hybrid. 我应该说也许，或者是混合的。 44:56 And instead of proof of work, the permissioned systems 而不是工作量证明，许可系统 44:59 use a bunch of consensus mechanisms. 使用一系列共识机制。 45:02 And I just listed a couple notary 我刚列出了一些公证人 45:04 nodes or PBFT for Byzantine Fault Tolerance again. 节点或PBFT用于拜占庭容错。 45:13 But they don't have native currencies. 但它们没有原生货币。 45:16 So that is a very big difference-- no native currency. 所以这是一个非常大的区别——没有原生货币。 45:21 If you have a solution for your final projects, 如果你有一个解决方案用于你的期末项目， 45:24 or you have a solution for some entrepreneurial business 或者你有一个解决方案用于某个创业业务 45:27 that you're going to do in the future 你将在未来进行的 45:29 that you want a native currency, you're probably more over 你想要原生货币，你可能更倾向于 45:32 into the permissionless world. 无许可的世界。 45:35 You want to have an incentive structure, something 你想要有一个激励结构，某种 45:37 to motivate customers or users, or create token economics. 来激励客户或用户，或者创建代币经济。 45:43 Token economics is more in the permissionless. 代币经济更多地存在于无许可中。 45:47 I say more because you can create a token even in the permissioned space. 我说更多是因为你甚至可以在许可空间中创建代币。 45:53 We'll talk about it in a moment. 我们稍后会谈到这个问题。 45:56 And then transaction script or UTXOs. 然后是交易脚本或UTXOs。 46:02 of permissioned systems, but you need some ledger. 许可系统，但你需要一些账本。 46:06 This last box, if I just called it ledgers, you'd still have ledgers in. 最后这个框，如果我只是称它为账本，你仍然会有账本在里面。 46:12 So it's really the consensus mechanism in the middle, as Emily said. 所以实际上是中间的共识机制，正如艾米莉所说的。 46:18 A couple of key design features. 几个关键设计特征。 46:22 First, membership's limited to basically an authorized set of nodes. 首先，成员资格基本上限于授权节点集。 46:27 So does anybody want to say, if you were a bank, 那么有没有人想说，如果你是一家银行， 46:31 who you might-- you know, what might you do if you were 你可能会做什么，如果你是 46:35 a bank, and who might you authorize if you're doing a bank-- I don't know. 一家银行，谁可能是你授权的对象——我不知道。 46:41 Let's say that it was loans, or if it's Mark Snyderman's real estate. 假设这是贷款，或者是马克·斯奈德曼的房地产。 46:47 It's real estate loans. 这是房地产贷款。 46:50 Could you ever see real estate loans going on a blockchain, Mark? 你能想象房地产贷款上链吗，马克？ 46:55 MARK SNYDERMAN: Loans, maybe. 马克·斯奈德曼：贷款，可能。 46:56 Loans could. 贷款可以。 46:57 PROFESSOR: All right. 教授：好的。 46:58 So-- MARK SNYDERMAN: Loans aren't traded as much. 所以——马克·斯奈德曼：贷款交易不多。 47:01 PROFESSOR: So if real estate loans were on a permissioned blockchain, 教授：所以如果房地产贷款在一个许可区块链上， 47:06 who might be that membership, the limited-- 那成员可能是谁，有限的—— 47:08 who would-- it's not just a rhetorical question. 谁会——这不仅仅是一个修辞性问题。 47:14 Who would actually care about the database of the loans? 谁会真正关心贷款的数据库？ 47:17 MARK SNYDERMAN: Broker dealers that 马克·斯奈德曼：活跃于贷款的经纪交易商， 47:19 are active in loans, institutional investors that are active in loans. 活跃于贷款的机构投资者。 47:27 PROFESSOR: So the broker dealers who 教授：所以那些实际上交易贷款的经纪交易商， 47:29 are actually trading the loans, and maybe the investors. 实际上在交易贷款，也许还有投资者。 47:31 Alon? 阿隆？ 47:32 AUDIENCE: Yeah. 观众：是的。 47:32 Just rating agencies when you securitize those loans-- AUDIENCE: Loan servicers. 当你将这些贷款证券化时，评级机构——观众：贷款服务商。 47:37 AUDIENCE: Loan servicers. 观众：贷款服务商。 47:37 PROFESSOR: Amanda, loan servicers. 教授：阿曼达，贷款服务商。 47:39 So maybe loan servicers, maybe the rating agencies. 所以可能是贷款服务商，也可能是评级机构。 47:42 So it's basically, who has a need and needs that data? 所以基本上，谁有需求并需要这些数据？ 47:47 I'm not sure that this is the right community, 我不确定这是否是正确的社区， 47:50 but it's the discussion I'm thinking about. 但这是我正在考虑的讨论。 47:52 And again, as you're thinking about-- 再一次，当你在思考—— 47:54 I'm jumping again to a little bit final projects, but when 我又跳到一些最终项目，但当 47:57 you're thinking about who actually needs data 你在思考谁实际上需要数据时 48:01 and who has a reason to amend the data, or write to the ledger-- 以及谁有理由修改数据或写入账本时—— 48:09 because if you don't have a desire and a need 因为如果你没有愿望和需求 48:10 to actually amend or change the data, move value in the system, 去实际修改或更改数据，在系统中移动价值， 48:18 you might not need an open database. 你可能不需要一个开放的数据库。 48:22 Please. 请。 48:22 AUDIENCE: When we were talking about 观众：当我们在谈论 48:24 that additional layer of blocks, is that layer also-- 那额外的区块层，那个层也是—— 48:27 can you change the membership with that layer? 你能通过那个层改变成员资格吗？ 48:33 PROFESSOR: I'm not sure I follow your question. 教授：我不确定我理解你的问题。 48:35 When you say an additional layer of blocks-- [INTERPOSING VOICES] 当你说额外的区块层时——[插话] 48:39 PROFESSOR: Oh, I'm sorry. 教授：哦，抱歉。 48:40 Layer 2. 第二层。 48:41 AUDIENCE: Yeah. 观众：是的。 48:42 Can you alter the-- because it's a different level of refinement of information 你能改变——因为这是信息的不同精细化层次 48:48 that's stored. 被存储。 48:50 PROFESSOR: So what Kelly is asking is, 教授：所以凯莉问的是， 48:53 we've talked about how to make permissionless 我们讨论了如何使无权限 48:57 blockchains more scalable by having a layer 2, like the Lightning Network. 区块链通过拥有第二层（如闪电网络）变得更具可扩展性。 49:02 That's what you're referencing. 这就是你所提到的。 49:04 So in permissionless systems, it's open to everyone, 所以在无权限系统中，向所有人开放， 49:09 even though if you're opening up an individual payment 即使你在闪电网络中打开一个单独的支付 49:13 channel in the Lightning Network, it's really just two counterparties 通道，它实际上只是两个交易对手 49:17 opening up a channel. 打开一个通道。 49:19 So in a sense, you've already narrowed the scope, 所以在某种意义上，你已经缩小了范围， 49:22 because you might just have a payment channel between two parties-- 因为你可能只是有一个在两个方之间的支付通道—— 49:26 some side chains or multiple parties. 一些侧链或多个方。 49:29 Lightning Network and payment channels tend to be two parties. 闪电网络和支付通道通常是两个方。 49:34 So I don't know if-- was that what you're asking? 所以我不知道——这就是你在问的吗？ 49:36 AUDIENCE: That network in and of itself is a mechanism of membership. 观众：那个网络本身就是一种成员机制。 49:45 PROFESSOR: The layer 2 can be a membership. 教授：第二层可以是一个成员资格。 49:47 That is correct. 这是正确的。 49:49 But it's a technology that's available to everybody. 但这是一项对所有人开放的技术。 49:52 So it has attributes where you can open up bilateral channels. 所以它具有可以打开双边通道的属性。 49:58 James. 詹姆斯。 49:58 AUDIENCE: I was just going to say, for permissioned blockchains, couldn't you 观众：我只是想说，对于许可区块链，你能不能想象一下 50:00 imagine that the layer 1 would be, say, the Fed 第一层可能是，比如说，美联储 50:04 with all of the big commercial banks? 与所有大型商业银行一起？ 50:07 But in effect, if you're thinking about a different layer, you could 但实际上，如果你考虑一个不同的层，你可以 50:09 have another layer on top of that, which [INAUDIBLE] central banks. 在其上再加一层，这一层是[听不清]中央银行。 50:13 So you could naturally-- PROFESSOR: All right. 所以你可以自然地——教授：好的。 50:14 AUDIENCE: --have two layers of deals with-- PROFESSOR: So where we're headed is, 观众：——有两层交易——教授：所以我们要讨论的是， 50:17 is do permissioned systems have the same need 许可系统是否有相同的需求 50:21 to have a second layer as permissionless? 与无许可系统一样需要第二层？ 50:26 And even if they don't have the same needs, might it actually provide something? 即使它们没有相同的需求，它是否实际上能提供一些东西？ 50:30 So I would say, I don't think they have the same need 所以我想说，我认为它们没有相同的需求 50:33 to have a second layer, because they're more scalable, 去拥有第二层，因为它们更具可扩展性， 50:36 they're more efficient right now. 它们现在更高效。 50:39 And they're already closed clubs. 而且它们已经是封闭的俱乐部。 50:43 But even if they don't have the same need, 但即使它们没有相同的需求， 50:46 they might actually want to put a second layer on top. 它们实际上可能想在上面加一层。 50:49 And some of them actually do this right in their technology. 而且它们中的一些确实在其技术中实现了这一点。 50:53 And it's what I put up here as the second and third bullet point. 这就是我在这里列出的第二和第三个要点。 50:58 The transactions can be limited to only authorized known participants. 交易可以仅限于授权的已知参与者。 51:03 So in many permissioned systems, it's a one broad technology. 因此，在许多许可系统中，它是一种广泛的技术。 51:08 It might only be 20 people that can authorize transactions. 可能只有20个人可以授权交易。 51:14 But now in some transactions, it will only be Anton and May. 但现在在某些交易中，只有安东和梅。 51:18 And in other transactions, it will be Alpha and Amanda. 而在其他交易中，将是阿尔法和阿曼达。 51:22 So I might not be able to-- by the way, Alpha might be Goldman Sachs, 所以我可能无法——顺便说一下，阿尔法可能是高盛， 51:27 and Amanda might be Barclays. 而阿曼达可能是巴克莱。 51:30 And then it might make more sense. 然后这可能更有意义。 51:32 And Mark might be Fidelity. 而马克可能是富达。 51:35 And I don't know, am I the US Department of Treasury in this one? 我不知道，我在这个中是美国财政部吗？ 51:42 Mark and I both started out in finance. 马克和我都从金融行业开始。 51:44 I just went off to public service later. 我后来只是去从事公共服务。 51:48 But so Corda and Hyperledger and many of the private blockchains 但是，Corda、Hyperledger和许多私有区块链 51:54 literally allow for partitioning right in the blockchain. 实际上允许在区块链中进行分区。 51:59 I don't know if you'd need to put a layer 我不知道你是否需要在上面加一层 52:00 2 on top, because they allow for partitioning and segregated 2，因为它们允许分区和隔离 52:05 pools of authority inside of the blockchain. 在区块链内部的权威池。 52:09 I'm sorry? 抱歉？ 52:09 There was a question, I thought. 我以为有个问题。 52:11 Oh. 哦。 52:12 Oh, yeah. 哦，是的。 52:13 AUDIENCE: [INAUDIBLE] you see insurance companies, 观众：[听不清]你认为保险公司， 52:15 like title insurance, as part of this. 比如产权保险，是这个的一部分。 52:17 PROFESSOR: Can you speak up? 教授：你能大声一点吗？ 52:18 [INAUDIBLE] AUDIENCE: Insurance companies for title for the houses-- PROFESSOR: Right. [听不清]观众：房屋产权的保险公司——教授：对。 52:22 AUDIENCE: --I think blockchain could be really helpful, 观众：——我认为区块链可能会非常有帮助， 52:25 because sometimes you have the trust issue around who 因为有时你会遇到关于谁的信任问题 52:28 owned the house before you, or the title where it goes backwards in history. 在你之前拥有房子的人，或者产权的历史追溯。 52:33 So I think title insurance companies 所以我认为产权保险公司 52:37 would be part of this blockchain in terms of [INAUDIBLE].. 将是这个区块链的一部分，涉及到[听不清]。 52:40 PROFESSOR: So your point is, is that titling of real estate 教授：所以你的观点是，房地产的产权 52:43 could be an important part of blockchains, and as [AUDIO OUT] 可能是区块链的重要组成部分，并且[音频中断] 52:49 MARK SNYDERMAN: Probably someday, 马克·斯奈德曼：可能有一天， 52:50 but every little town has its own system for keeping property records. 但每个小镇都有自己的财产记录保存系统。 52:56 And getting them all to cooperate in a blockchain kind of solution seems remote. 让它们都在区块链解决方案中合作似乎很遥远。 53:05 They don't think they have a real problem that needs solving. 他们认为自己没有真正需要解决的问题。 53:07 So yeah, maybe someday. 所以，是的，也许有一天。 53:10 But I doubt it will happen anytime soon. 但我怀疑这会很快发生。 53:13 But it makes some logical sense. 但这在逻辑上是有意义的。 53:17 And that would probably be a permissionless system, 而这可能是一个无许可系统， 53:20 because there's not a huge amount of times a piece of property transacts, right? 因为一块财产交易的次数并不多，对吧？ 53:27 So it's not like moving money around the world. 所以这不像是在全球范围内转移资金。 53:31 It's a much simpler, less frequent event. 这是一件更简单、发生频率更低的事情。 53:35 AUDIENCE: Yeah-- MARK SNYDERMAN: And land records are public. 观众：是的——马克·斯奈德曼：而土地记录是公开的。 53:38 People often have to go to the town offices to look at them. 人们通常需要去市政办公室查看它们。 53:42 AUDIENCE: Yeah, you have to pay a lot of transaction fees, 观众：是的，你必须支付很多交易费用， 53:45 whether you're transacting on a plant or anything that involves 无论你是在进行植物交易还是任何涉及 53:49 real estate here in the US. 美国的房地产交易。 53:51 You have to pay considerable amount of fees to the title insurance companies. 你必须向产权保险公司支付相当可观的费用。 53:56 And in my mind, that could eliminate that role 在我看来，这可以消除这个角色 53:59 if you have blockchain and [INAUDIBLE] where the system. 如果你有区块链和[无法听清]的系统。 54:05 MARK SNYDERMAN: Maybe, but you're paying money 马克·斯奈德曼：也许吧，但你在支付费用 54:08 because you're asking-- AUDIENCE: Somebody to-- 因为你在要求——观众：某人来—— 54:11 MARK SNYDERMAN: --them and lawyers to make sure the title's free and clear. 马克·斯奈德曼：——他们和律师来确保产权是清晰无误的。 54:16 AUDIENCE: [INAUDIBLE] MARK SNYDERMAN: And there's all sorts of claims on a title to property-- 观众：[无法听清]马克·斯奈德曼：而且产权上有各种各样的索赔—— 54:20 somebody that fixed the roof, or the utility company 有人修了屋顶，或者公用事业公司 54:23 that has an easement through the middle to put lines and so forth. 在中间有一个通行权来铺设线路等等。 54:30 So there are some complications that are different than just transferring money. 所以有一些复杂性与仅仅转移资金是不同的。 54:37 PROFESSOR: So to bring it back, to broaden it out, the que-- it's Rahim? 教授：那么回到正题，扩展一下，问题是——是拉希姆吗？ 54:44 AUDIENCE: Rahem. 观众：拉赫姆。 54:44 PROFESSOR: Rahem. 教授：拉赫姆。 54:45 Rahem's question is, is, well, what about real estate and title? 拉赫姆的问题是，嗯，房地产和产权呢？ 54:49 Might that be appropriate? 这可能合适吗？ 54:50 And as Mark has given us a sense of, yes, it might be. 正如马克所说的，是的，这可能是。 54:55 But we're back to that sort of thing of the collective action 但我们又回到了集体行动的问题 54:58 issues that we've talked about in previous classes-- 我们在之前的课程中讨论过的集体行动问题—— 55:01 the collective action of many municipal authorities 许多市政当局的集体行动 55:07 that keep the land records, that keep the real estate records. 维护土地记录，维护房地产记录。 55:10 Yeah, it might help, but why do I need to do this? 是的，这可能有帮助，但我为什么需要这样做？ 55:15 And it's also a [INAUDIBLE]. 而且这也是一个[无法听清]。 55:16 It's a low volume, low transaction. 这是一个低交易量，低交易的情况。 55:20 And yet, it could be an enormous benefit, 然而，这可能带来巨大的好处， 55:23 because there's something called title insurance. 因为有一种叫做产权保险的东西。 55:25 And title insurance trying to clean up the title 而产权保险试图清理产权 55:28 and making sure that something is free and clear 并确保某些东西是清晰无误的 55:32 could be recorded in the future. 可以在未来被记录。 55:35 So I'll be a long-term optimist. 所以我会是一个长期的乐观主义者。 55:37 I don't see this one being solved in the next handful 我认为在接下来的几年里，这个问题不会得到解决 55:40 of years-- single digit years-- 在单数年份内—— 55:42 particularly because of the [INAUDIBLE] collective action issues. 特别是因为[无法听清]的集体行动问题。 55:45 I'm sorry. 抱歉。 55:46 We have somebody here who's going 我们这里有一个人要 55:47 to take the other side before I give my conclusionary estimate. 在我给出我的结论性估计之前，提出反方观点。 55:52 Yes? 是吗？ 55:53 AUDIENCE: Yes. 观众：是的。 55:54 That's exactly my startup. 这正是我的初创公司。 55:55 The first phase is collecting all the data 第一阶段是收集所有数据 55:59 from all those munis departmentals [INAUDIBLE].. 来自所有那些市政部门的[无法听清]。 56:02 The information is there publicly. 这些信息是公开的。 56:04 So yes, they will not probably immediately adopt a Corda node 所以是的，他们可能不会立即采用Corda节点 56:08 and record their stuff. 并记录他们的东西。 56:10 But you can publicly pool that information 但你可以公开汇集这些信息 56:13 and then use that information and record that information on the blockchain. 然后使用这些信息并在区块链上记录这些信息。 56:17 And then once I become stronger and bigger, 然后一旦我变得更强大和更大， 56:21 then they will probably have to adopt it. 他们可能就必须采用它。 56:23 PROFESSOR: All right. 教授：好的。 56:24 [LAUGHTER] So maybe I'll move up my estimate [笑声] 所以也许我会将我的估计提高 56:27 from double digit years to single digit years. 从双位数年份提高到单位数年份。 56:30 But I think it's going to be, with all respect, some time. 但我认为，恕我直言，这将需要一些时间。 56:35 Pria, then I'm going to move on. 普里亚，然后我将继续。 56:36 AUDIENCE: So I used to work at Habitat for Humanity International. 观众：我曾在国际人道主义住房协会工作。 56:40 So access to proper land rights or land 因此，获得适当的土地权利或土地 56:43 title, that was a big issue for us overseas, not so much in the US. 产权，对我们在海外来说是一个大问题，而在美国则不那么重要。 56:47 And so I could see a real application there, 因此，我可以看到在那里的实际应用， 56:49 where in several countries where there is no land record, 在几个没有土地记录的国家， 56:52 or there are no title systems, or they're buried in layers of obfuscation. 或者没有产权系统，或者它们被埋在层层模糊之中。 56:57 This is a great solution to get something 这是一个很好的解决方案，可以在这些背景下启动某些东西， 56:59 like that started in those contexts, where there is-- 在这些背景下，建立产权记录可能具有不可估量的社会价值。 57:05 establishing the property right of record could be of immeasurable social value. 建立产权记录可能具有不可估量的社会价值。 57:10 PROFESSOR: You know, I agree, and I 教授：你知道，我同意，我 57:12 think there's been a tremendous amount of literature 认为已经有大量的文献 57:15 in the last 24 months around whether blockchain 在过去的24个月中，关于区块链是否 57:18 can help free up a lot of illiquid capital and assets. 可以帮助释放大量非流动资本和资产的讨论。 57:25 I'm just saying I'm probably closer to Mark's thinking than to Alon's thinking. 我只是想说，我可能更接近马克的想法，而不是阿隆的想法。 57:31 I think it's going to take some time. 我认为这需要一些时间。 57:33 AUDIENCE: But depending on the context, right? 观众：但这要看具体情况，对吧？ 57:35 In the context-- PROFESSOR: Context, the country, the system, the legal system, 在这种情况下——教授：上下文、国家、系统、法律系统， 57:40 how decentralized, and how tough the collective action issues are. 去中心化的程度，以及集体行动问题的难度。 57:45 So just going back to private blockchains, technical features-- let's go back. 所以回到私有区块链，技术特性——我们回到这里。 57:51 Membership limited to authorized nodes. 成员资格仅限于授权节点。 57:55 Transactions can be partitioned as well. 交易也可以被分区。 57:58 It's kind of Kelly's point. 这有点像凯莉的观点。 58:00 Right in the technology, you can partition and segregate information. 在技术上，你可以对信息进行分区和隔离。 58:05 So data and ledgers can be partitioned because transactions can be partitioned. 因此，数据和账本可以被分区，因为交易可以被分区。 58:11 That doesn't mean you can't have a layer 2. 这并不意味着你不能有一个层2。 58:13 I'm just saying there's a lot less need for a layer 2, 我只是想说，层2的需求要少得多， 58:15 because they do it in the data structures itself. 因为他们在数据结构中就能做到这一点。 58:19 The consensus is permissioned private protocols. 共识是许可的私有协议。 58:24 They do have a consensus. 他们确实有共识。 58:26 Somebody has to agree on the next block. 必须有人同意下一个区块。 58:31 But it's a tight, limited group. 但这是一个紧密而有限的群体。 58:35 It does use cryptography, but often, there's 它确实使用了加密技术，但通常有 58:38 something called a registration authority. 一种被称为注册机构的东西。 58:40 The registration authority is helping mask data. 注册机构帮助掩盖数据。 58:46 So they address privacy two ways. 因此，他们通过两种方式来解决隐私问题。 58:50 They address privacy because it's a smaller group. 他们解决隐私问题是因为这是一个较小的群体。 58:53 They can actually see the whole network. 他们实际上可以看到整个网络。 58:56 But even within the network, even on the network, 但即使在网络内部，即使在网络上， 59:00 they're further addressing privacy that Alpha's and my transaction, Amanda maybe 他们进一步解决隐私问题，阿尔法和我的交易，阿曼达可能 59:09 can't even see, even though she's on the network, because it's encrypted. 甚至看不到，即使她在网络上，因为它是加密的。 59:14 And then there's sort of what's called a registration 然后有一种被称为注册的东西 59:16 authority, or authority within the system, that can unmask it. 或者系统内的权威，可以揭示它。 59:23 Yes. 是的。 59:24 AUDIENCE: I just have a question about the-- 观众：我只是想问一下—— 59:26 how is a segregated system a subgroup of two [INAUDIBLE] different from a layer? 一个分隔系统的两个[听不清]子组与一个层有什么不同？ 59:33 If [INAUDIBLE] is already doing subnetting off of calculations, 如果[听不清]已经在进行计算的子网划分， 59:37 or whatever it may be-- transactions-- 或者不管是什么——交易—— 59:39 and then the net [INAUDIBLE]-- PROFESSOR: All right. 然后网络[听不清]——教授：好的。 59:42 So I've got another question I have to follow up on. 所以我还有一个问题需要跟进。 59:45 I have to follow up on Brotish's Corda question, 我需要跟进Brotish关于Corda的问题， 59:47 and now James' question about, well, wait a minute. 还有詹姆斯的问题，等等。 59:50 How is this partitioning different than a layer 2? 这种分区与层2有什么不同？ 59:53 And it's beyond my knowledge, but I'm going to see if I can get it for you. 这超出了我的知识范围，但我会看看能否为你解答。 59:58 That's a good-- they're both-- they're good questions. 这是个好问题——这两个问题都很好。 60:03 And then smart contracts-- yes, smart contracts 然后智能合约——是的，智能合约 60:07 can happen on these systems as well as permissionless systems. 可以在这些系统以及无权限系统上发生。 60:14 IBM-- they say they use chaincode. IBM——他们说他们使用链码。 60:16 But they say chaincode really could be any language, at least 但他们说链码实际上可以是任何语言，至少 60:20 they advertise, and no native currency. 他们这样宣传，并且没有原生货币。 60:24 So that's kind of the technical-- not deeply technical. 所以这算是技术上的——不是很深入的技术。 60:27 It's not like learning hash functions. 这并不像学习哈希函数那样。 60:29 But yes to cryptography. 但确实涉及到加密技术。 60:32 Well, they partition the ledgers. 好吧，他们对账本进行了分区。 60:35 The consensus is closed loop. 共识是闭环的。 60:37 Yes, they have smart contracts. 是的，他们有智能合约。 60:40 But they can even have additional privacy. 但他们甚至可以有额外的隐私。 60:42 But it comes at a cost. 但这是有代价的。 60:45 There's an authority that has to protect 有一个权威必须保护 60:47 something-- a registration authority inside of it. 某种东西——内部的注册机构。 60:51 Oh, I forgot. 哦，我忘了。 60:53 The code is generally open source. 代码通常是开源的。 60:54 It does not have to be open source. 它不一定是开源的。 60:56 Hyperledger is open source, but it doesn't have to be open source. Hyperledger是开源的，但它不一定是开源的。 61:03 So this was from one of the readings. 所以这是来自其中一篇阅读材料。 61:06 I'm just putting up that chart that was in the reading. 我只是把阅读材料中的那张图表放上来。 61:08 And I just found it helpful. 我觉得这很有帮助。 61:09 It's a different way. 这是一种不同的方式。 61:10 It's not Gensler's way. 这不是Gensler的方式。 61:12 It's somebody else's way of thinking about Ethereum, Hyperledger, and Corda. 这是其他人对以太坊、Hyperledger和Corda的思考方式。 61:16 I'm only using Hyperledger and Corda 我只使用Hyperledger和Corda 61:18 because they're two of the biggest private platforms. 因为它们是两个最大的私有平台。 61:22 There are many others. 还有许多其他平台。 61:26 Different programming language-- you 不同的编程语言——你 61:28 might say, from a business point of view, who cares? 可能会说，从商业角度来看，谁在乎？ 61:32 And to some level, you're probably right. 在某种程度上，你可能是对的。 61:35 But you're not completely right. 但你并不是完全正确。 61:37 I mean, there's probably more that people can write 我的意思是，人们可能可以在 61:41 on top of Hyperledger Fabric. Hyperledger Fabric上写更多的东西。 61:43 They say more developers could work on that than Solidity. 他们说，更多的开发者可以在那上面工作，而不是Solidity。 61:49 Governance-- that's the governance of the system itself. 治理——这是系统本身的治理。 61:55 They all can do smart contracts. 它们都可以执行智能合约。 61:57 We've talked about consensus. 我们谈过共识。 62:00 And the scalability is much harder. 而可扩展性要困难得多。 62:02 Ethereum, remember, almost crashed on CryptoKitties last December. 记住，以太坊在去年12月几乎因CryptoKitties崩溃。 62:08 And I shared that story about one initial coin offering 我分享了一个关于某个首次代币发行的故事 62:11 was 30% of the Ethereum network on the one day it was closing [INAUDIBLE]. 在它关闭的那一天，占据了以太坊网络的30% [听不清]。 62:19 DTCC, in a given day, can do as much as 100 million transactions in a day. DTCC在一天内可以处理多达1亿笔交易。 62:28 That's the Depository Trust Corporation. 那是存托信托公司。 62:33 Ethereum does about a million and a half transactions a day, 以太坊每天大约处理150万笔交易， 62:37 and Bitcoin, about 400,000 to 500,000 transactions a day. 而比特币每天大约处理40万到50万笔交易。 62:42 So you know, we've still got a ways to go on this scalability. 所以你知道，在可扩展性方面我们还有很长的路要走。 62:49 So what about traditional databases? 那么传统数据库呢？ 62:51 I think that to talk about permissioned versus permissionless, a lot of people, 我认为谈论许可与无许可时，很多人， 62:56 even some of my colleagues here at MIT, 甚至我在麻省理工学院的一些同事， 62:58 says, well, if you're talking about Hyperledger, Corda, 会说，如果你谈论Hyperledger、Corda， 63:01 and Fabric and Corda, that's like Oracle. 和Fabric和Corda，那就像Oracle。 63:06 That's just a traditional database. 这只是一个传统数据库。 63:08 That's not really blockchain. 这并不是真正的区块链。 63:11 The Bitcoin and blockchain purist 比特币和区块链的纯粹主义者 63:13 would say, if it doesn't have Nakamoto consensus, forget it. 会说，如果没有中本聪共识，那就算了。 63:20 It's not a member of the club. 它不是俱乐部的成员。 63:22 That's not how I've chosen to teach that this class, as you know. 正如你所知，这不是我选择教授这门课的方式。 63:27 I think both are relevant, possibly, 我认为两者都是相关的，可能， 63:29 to business solutions, and it's worthwhile to think of them. 对商业解决方案都是有价值的，值得考虑它们。 63:32 But so what separates-- and this is not in the reading, so I'm just going to, 但那么，是什么将它们区分开来——这在阅读材料中没有，所以我只是要， 63:38 you know, kind of-- but what separates it versus a traditional database? 你知道，有点——但是什么将它与传统数据库区分开来？ 63:43 Well, back to the basics. 好吧，回到基础。 63:46 Permissioned private blockchains have append-only logs. 许可的私有区块链具有仅追加日志。 63:50 You're adding-- I know. 你在添加——我知道。 63:52 Thank you, Brotish. 谢谢你，Brotish。 63:54 But basically, they have append-only logs. 但基本上，它们具有仅追加日志。 63:59 Traditional databases-- and I'm at the edge of my knowledge-- you can create. 传统数据库——我在我的知识边缘——你可以创建。 64:03 You can read. 你可以读取。 64:04 You can update. 你可以更新。 64:05 You can delete. 你可以删除。 64:08 Again, I'm taking the mainstream traditional databases, 再说一次，我在谈论主流的传统数据库， 64:12 or what's called CRUD, if you wish-- 或者如果你愿意，可以称之为CRUD—— 64:15 C-R-U-D. Whereas these, you always are adding to the database. C-R-U-D。而这些，你总是向数据库添加数据。 64:25 Two, these databases use cryptography to have commitment schemes. 其次，这些数据库使用加密技术来实现承诺方案。 64:30 You may remember, what is a hash function? 你可能还记得，什么是哈希函数？ 64:33 It not only compresses data, but it means you're committing to the data. 它不仅压缩数据，还意味着你在对数据进行承诺。 64:39 And when you finish The New York Times crossword puzzle, 当你完成《纽约时报》的填字游戏时， 64:42 you can actually send it in. 你实际上可以将其发送出去。 64:43 And if it's identical to-- and hash it. 如果它是相同的——并进行哈希。 64:47 And if you remember our discussion about The New York 如果你还记得我们关于《纽约时报》 64:49 Times crossword puzzle, if it's hashed, and the hashes match, voilá. 填字游戏的讨论，如果它被哈希，并且哈希匹配，瞧。 64:54 You solved The New York Times crossword puzzle. 你解决了《纽约时报》的填字游戏。 64:57 So you can have commitment schemes for the data. 所以你可以对数据进行承诺方案。 65:02 And it can be distributed. 而且它可以是分布式的。 65:04 Yes, Joequinn. 是的，Joequinn。 65:06 AUDIENCE: So even if it's append-only, if you take away the proof of work, 观众：所以即使它是仅追加的，如果你去掉工作量证明， 65:11 you can rewrite it in a very quick manner. 你可以以非常快速的方式重写它。 65:16 PROFESSOR: So Joequinn's raising a very important point. 教授：所以乔奎因提出了一个非常重要的观点。 65:19 So even if it's append-only, you get rid of proof of work, 即使它是仅追加的，你去掉了工作量证明， 65:23 can't somebody go in and rewrite it? 难道没有人可以进去重写它吗？ 65:26 Permissioned blockchains make a different trade-off on trust. 许可区块链在信任上做出了不同的权衡。 65:33 Permissionless system say, we're going to address trust 无许可系统说，我们将通过这种工作量证明来解决信任问题。 65:36 through this proof of work. 通过这种工作量证明。 65:38 And at least 51% of all of the network 并且网络中至少51%的人 65:42 has to, in essence, agree and validate, and the like. 本质上必须同意并验证，等等。 65:46 Permissioned basically are saying, I'm going to trust the 10 or 15 or 20 许可的基本上是说，我将信任系统中的10、15或20个 65:53 nodes that are in the system can validate against each other. 节点可以相互验证。 65:58 And so there's something about the club that's authorized in the network. 因此，网络中有一些关于被授权的俱乐部的内容。 66:06 But they're still using append-only. 但他们仍然使用仅追加。 66:08 You're right that within those 20, somebody could try to rush through and do 你说得对，在这20个节点中，有人可能会试图快速进行并做 66:13 a whole entire new append-only. 一个全新的仅追加。 66:16 But then within the club, it's exposed. 但在俱乐部内部，这就暴露了。 66:22 AUDIENCE: If the club agrees that the last two 观众：如果俱乐部同意过去两天 66:24 days have to be rewritten, they can do it in a very easy way. 必须重写，他们可以非常简单地做到这一点。 66:29 PROFESSOR: Correct. 教授：正确。 66:30 But I would contend that even in Bitcoin, 但我认为即使在比特币中， 66:32 if 10,000 nodes decided to rewrite the last two days, they could. 如果10000个节点决定重写过去两天，他们是可以的。 66:38 It's a-- AUDIENCE: Taken a lot of time, because they have-- PROFESSOR: Yes. 这需要很长时间，因为他们有——教授：是的。 66:41 AUDIENCE: --to find-- PROFESSOR: That's correct. 观众：——找到——教授：没错。 66:43 AUDIENCE: [INAUDIBLE] PROFESSOR: That's correct. 观众：[听不清]教授：没错。 66:45 So what Joequinn's saying is in Bitcoin, 所以乔奎因所说的是在比特币中， 66:47 what protects against that is partly the proof of work, 保护这一点的部分是工作量证明， 66:51 and partly that it takes 10,000, or at least 51% of them, 部分是需要10000个，或者至少51%的人， 66:55 probably, to rewrite the last two days. 可能需要重写过去两天。 66:58 The economic incentives in Bitcoin 比特币中的经济激励 67:00 is, is why waste all your computer power and electricity 就是，为什么要浪费你所有的计算机算力和电力 67:04 and so forth doing that when you may as well just go forward? 去做这些事情，而不如继续前进？ 67:09 I think Bitcoin could be susceptible to state actors. 我认为比特币可能会受到国家行为者的影响。 67:14 I think, you know, if North Korea wanted-- 我认为，如果朝鲜想要—— 67:17 or Russia wanted-- to spend probably single digit billions, 或者俄罗斯想要——花费可能是十亿的单数， 67:21 but at most maybe 10 billion, they could overwhelm the whole system and bring-- 但最多可能是100亿，他们可以压倒整个系统并带来—— 67:27 they could do a 51% attack by buying up enough mining equipment, the ASICs, 他们可以通过购买足够的矿机，ASICs，进行51%攻击， 67:34 and just bigfooting the whole system. 并且直接控制整个系统。 67:37 But it's multiple billio-- and there's academic papers on this now. 但这需要数十亿——现在有关于此的学术论文。 67:41 It's single digit billions. 这是十亿的单数。 67:42 A state actor could-- an individual wouldn't want to do it, 国家行为者可以——个人不想这样做， 67:47 because you'd crush $110 billion market cap down to [INAUDIBLE].. 因为你会把1100亿美元的市值压缩到[听不清]。 67:51 So that would be kind of unwise. 所以这将是相当不明智的。 67:57 This is a very critical part of what a private blockchain-- 这是私有区块链的一个非常关键的部分—— 68:02 to me, economically, what a private blockchain 在我看来，从经济上讲，私有区块链 68:04 can do and facilitate better than a traditional database. 可以做的事情以及比传统数据库更好地促进的事情。 68:09 I'm not saying this list is the only list. 我并不是说这个列表是唯一的列表。 68:11 I'm not even saying this list is completely the right list. 我甚至不说这个列表是完全正确的列表。 68:14 This is Gary Gensler's list trying to say, what's the business that separates 这是加里·根斯勒的列表，试图说明，什么是将 68:20 traditional blockchains? 传统区块链分开的业务？ 68:22 Append-only timestamping. 仅追加时间戳。 68:25 Some cryptography and schemes that 一些加密技术和方案 68:29 makes the data immutable so you can put it in a ledger-- 使数据不可变，以便你可以将其放入账本中—— 68:35 so it's back to ledgers and so forth-- and thus, finality of settlement. 所以又回到了账本等等——因此，结算的最终性。 68:40 Does anybody want to remind the class what settlement means? 有没有人想提醒一下班级结算是什么意思？ 68:46 Anybody? 有人吗？ 68:47 Take a shot. 来试试。 68:49 Where's my accountant? 我的会计在哪里？ 68:52 Aviva's not here. 阿维瓦不在这里。 68:55 Oh, please. 哦，拜托。 68:58 AUDIENCE: [INAUDIBLE] do with the UTXO. 观众：[听不清]与UTXO有关。 69:02 PROFESSOR: No, forget about UTXO. 教授：不，忘记UTXO。 69:04 Just tell me what settlement means. 只告诉我结算是什么意思。 69:06 AUDIENCE: Oh, like, making off your debit and credit. 观众：哦，就像，结算你的借记和信用。 69:09 PROFESSOR: Yeah, debits and credits. 教授：是的，借方和贷方。 69:12 Settlement means changing the data in a ledger, and doing it with finality. 结算意味着在账本中更改数据，并且是最终的。 69:21 In essence, do I have $10 or $11? 本质上，我是有10美元还是11美元？ 69:26 A payment settlement system is when you finally say, 支付结算系统就是当你最终说， 69:30 I've got $11, no longer $10. 我有11美元，不再是10美元。 69:33 And Amanda's got $9 instead of $10. 而阿曼达有9美元，而不是10美元。 69:38 You went down. 你减少了。 69:39 I went up. 我增加了。 69:40 Is that all right? 这样可以吗？ 69:41 AUDIENCE: Yeah. 观众：可以。 69:42 PROFESSOR: Thank you. 教授：谢谢。 69:43 You'll hear a lot about clearing and settlement. 你会听到很多关于清算和结算的内容。 69:46 The word settlement means to finally change “结算”这个词意味着最终更改 69:48 the data in a ledger, and that we're not going to come back to it. 账本中的数据，并且我们不会再回到它。 69:53 It's done. 这已经完成。 69:54 It's final. 这是最终的。 69:56 If we're moving something of value-- and the value could be grapes. 如果我们在转移某种有价值的东西——而这个价值可能是葡萄。 70:01 The value could be diamonds. 这个价值可能是钻石。 70:03 The value can be real estate. 这个价值可以是房地产。 70:04 The value can be money. 这个价值可以是货币。 70:05 But if we're moving something of value 但是如果我们在转移某种有价值的东西 70:08 and storing it on a ledger, it's more adaptable to blockchain. 并将其存储在账本上，它更适合区块链。 70:16 If you're doing some database that 如果你在做一些与 70:18 has nothing to do with things of value and ledger, 有价值的东西和账本无关的数据库， 70:21 you don't need final immutable settlement. 你不需要最终不可变的结算。 70:26 I would contend you probably have less reason 我认为你可能没有太多理由 70:28 to use any of this blockchain stuff. 使用任何这些区块链的东西。 70:32 Zan. 赞。 70:33 AUDIENCE: Can you maybe talk a little bit 观众：你能谈谈 70:35 about a real-world implementation of this? 这个的实际应用吗？ 70:38 So I saw recently that Walmart is forcing their suppliers 所以我最近看到沃尔玛正在强迫他们的供应商 70:41 to basically add themselves into this private blockchain 基本上将自己添加到这个私有区块链中 70:45 to basically track their supply chain. 以基本跟踪他们的供应链。 70:48 I'm having a really hard time understanding 我很难理解 70:49 why that needs to be on a blockchain, whether permissioned or nonpermissioned, 为什么这需要在区块链上，无论是许可的还是非许可的， 70:54 and why that needs to be. 以及为什么需要这样。 70:56 PROFESSOR: So the question is, why is Walmart 教授：所以问题是，为什么沃尔玛 70:59 putting supply chain with a bunch of agricultural products on a blockchain? 将供应链与一堆农产品放在区块链上？ 71:03 Agricultural products are something of value, whether it's corn, wheat, grapes. 农产品是有价值的东西，无论是玉米、小麦还是葡萄。 71:13 It's something of value. 这是一种有价值的东西。 71:14 And when it moves from one owner to another owner, 当它从一个所有者转移到另一个所有者时， 71:18 if you keep that on a ledger, you can record that Amanda has the grapes, 如果你把它保存在账本上，你可以记录阿曼达有葡萄， 71:23 and Gary no longer has the grapes. 而加里不再拥有这些葡萄。 71:26 And another thing that blockchains help with 区块链还有一个帮助的地方 71:31 is they lower the cost of reconciling multiple databases. 就是降低了对多个数据库进行对账的成本。 71:36 We could keep-- as in agriculture-- 我们可以保持——就像农业一样—— 71:39 we can keep separate ledgers, separate databases. 我们可以保持单独的账本，单独的数据库。 71:44 The farmers keeping their database. 农民保持他们的数据库。 71:48 The wholesaler with the grain elevators 批发商与粮食电梯 71:50 are keeping their database, and up the supply chain, 保持他们的数据库，沿着供应链， 71:54 from the farm, to the grain elevator, to the millers and merchants, all the way 从农场到粮食电梯，再到磨坊和商人，一直到 71:58 to General Mills, all the way to Kroger and the store. 通用磨坊，直到克罗格和商店。 72:04 Right now, those are multiple databases that, by and large, 现在，这些是多个数据库，基本上 72:08 don't have to communicate. 不需要进行通信。 72:10 So the question is, will Walmart get to the place where that's a good idea? 所以问题是，沃尔玛会不会达到那种好的想法？ 72:15 But I'm just pointing out if you're moving things of value 但我只是指出，如果你在转移有价值的东西 72:22 where you want to keep final settlement that you know who 你想保持最终结算，你知道谁 72:25 owns that thing of value in ledgers, 在账本中拥有那个有价值的东西， 72:29 and lastly, if you want to lower any reconciliation-- 最后，如果你想降低任何对账—— 72:37 if you have multiple ledgers and things of value, 如果你有多个账本和有价值的东西， 72:41 blockchain, I think, is more valuable. 我认为区块链更有价值。 72:47 Zan's asking, well, is that Walmart? 赞在问，这就是沃尔玛吗？ 72:49 I don't know. 我不知道。 72:49 We're going to find out. 我们会找到答案。 72:51 Tom, and I've got about seven minutes to finish. 汤姆，我还有大约七分钟来结束。 72:53 AUDIENCE: There was a talk last year. 观众：去年有一个演讲。 72:54 Somebody [INAUDIBLE] came in and talked about the-- 有人[听不清]进来谈论这个-- 72:57 they were then piloting this program. 他们当时正在试点这个项目。 72:59 But the example they used was, in E. coli outbreak 但他们使用的例子是，在大肠杆菌爆发中 73:01 in their spinach supply, rather than taking a whole supplier, 在他们的菠菜供应中，而不是将整个供应商 73:05 an entire wholesaler offline and recalling 整个批发商下线并召回 73:08 all of that product, through the blockchain, 所有产品，通过区块链， 73:10 they could trace it to a particular farm 他们可以追溯到特定的农场 73:12 and a single point of origin almost instantaneously 以及几乎瞬时的单一来源 73:16 and just take off a much smaller portion of it. 并且只取出其中一个更小的部分。 73:18 PROFESSOR: So let me do this. 教授：那么让我这样做。 73:19 Let me just-- hold on. 让我先等一下。 73:20 I know we've got two questions here. 我知道我们这里有两个问题。 73:21 Let me just hold on, just for-- is that all right? 让我先等一下，可以吗？ 73:24 All right. 好的。 73:25 We got permission. 我们得到了许可。 73:26 So this was what we talked about earlier-- Coase's trade-offs of costs. 所以这是我们之前谈论的内容——科斯的成本权衡。 73:34 Let me try another one, which is going 让我再试一个，这将是我对区块链和传统数据库的看法。 73:36 to be my shot at blockchains and traditional databases. 这将是我对区块链和传统数据库的看法。 73:41 So one is access control. 所以一个是访问控制。 73:43 Who has access to the ledger? 谁可以访问账本？ 73:45 Who has access, if I might, to the data? 谁可以访问数据，如果可以的话？ 73:50 Three different types of approaches we talked about-- 我们讨论了三种不同类型的方法—— 73:53 open permissionless, multiple permissioned, and client server. 开放的无权限、多重权限和客户端-服务器。 73:57 I'm using the word client server just to say traditional database. 我使用“客户端-服务器”这个词只是为了表示传统数据库。 74:01 You can use another words. 你可以使用其他词。 74:03 But I'm just trying to say three different types of data structures. 但我只是想说三种不同类型的数据结构。 74:07 And to Zan's question, why would you be in one bucket versus another? 对于赞的问题，为什么你会在一个类别而不是另一个类别？ 74:11 And I'm saying this. 我这样说。 74:12 If you're a venture capitalist one day, 如果你有一天是风险投资家， 74:15 and somebody comes in to you with a blockchain solution, this is the same thing. 而有人向你提出一个区块链解决方案，这就是同样的事情。 74:20 Hopefully, you'll make it better. 希望你能让它更好。 74:22 This is just my approach to it. 这只是我对它的看法。 74:24 Public blockchain-- do you need, basically, 公共区块链——你基本上需要， 74:29 public write capability, that lots of people can write to these ledgers? 公共写入能力，很多人可以写入这些账本？ 74:34 Do you need that somewhere? 你需要在某个地方吗？ 74:36 Secondly, do you want some peer to peer transaction capability 其次，你想要一些点对点交易能力 74:39 across the distributed ledger? 在分布式账本上？ 74:44 Do you kind of not want any central intermediary? 你是否不想要任何中央中介？ 74:46 Maybe you don't want the central intermediary because they're slow and sluggish. 也许你不想要中央中介，因为他们缓慢而迟钝。 74:49 Maybe you don't want the central intermediary 也许你不想要中央中介 74:51 because they have a lot of economic rents. 因为他们有很多经济租金。 74:53 It doesn't matter to me why you want to get rid of the central intermediary. 我不在乎你为什么想要去掉中央中介。 74:57 But if you want to get rid of a central intermediary, 但如果你想去掉中央中介， 74:59 or lessen their control, or lower their control, 或者减少他们的控制，或降低他们的控制， 75:02 raise peer to peer transactions, have a lot of public writing-- 增加点对点交易，进行大量公共写入—— 75:06 oh, and by the way, if you want some token economics, 哦，顺便说一下，如果你想要一些代币经济学， 75:09 you're probably somewhere over here. 你可能就在这里的某个地方。 75:11 I'm not saying you have to have all four. 我不是说你必须拥有所有四个。 75:13 But to me, those are the kind of three or four things that are floating around 但对我来说，这些是你可能在考虑的三到四个方面 75:18 why you might be over there. 为什么你可能会在那边。 75:21 Private blockchains-- well, maybe you actually 私有区块链——好吧，也许你实际上 75:23 don't want public write capability. 不想要公共写入能力。 75:25 You need private. 你需要私有。 75:27 Whether it's just the Australian Stock Exchange or 15 to 20 club 无论是澳大利亚证券交易所还是15到20个俱乐部 75:32 deal, you still want kind of multiple people to write, 交易，你仍然希望有多个参与者写入， 75:36 but you want it to be private. 但你希望它是私有的。 75:39 But if you still need finality of data and an append-only log, 但如果你仍然需要数据的最终性和仅追加日志， 75:46 that you need this appending-- the log, and you need some public verifiability, 你需要这个追加——日志，并且你需要一些公共可验证性， 75:53 that you still need that data to be verified amongst-- 你仍然需要这些数据在之间被验证—— 75:55 and this public means 15 or 20 players. 而这个公共意味着15或20个参与者。 75:59 But you need it to be able to be verified-- 但你需要它能够被验证—— 76:02 so the trust mechanism is not thousands and open. 所以信任机制不是成千上万的开放。 76:05 The trust mechanism is 15 or 20 or 5 parties. 信任机制是15、20或5个参与方。 76:08 But you still need it-- you might be there. 但你仍然需要它——你可能就在那儿。 76:11 Where I come out is there's some cases that you just don't need any of this. 我认为有些情况下你根本不需要这些。 76:17 There's a trusted party that hosts the data. 有一个可信的第三方来托管数据。 76:21 Your trust mechanism is one party. 你的信任机制是一个单一的参与方。 76:23 The trusted party can do the-- I use the letters CRUD. 这个可信的第三方可以执行——我用CRUD这个术语。 76:27 That's the create, and update, and delete, and so forth. 这就是创建、更新、删除等操作。 76:36 And that's based on client service architecture, 这基于客户端服务架构， 76:40 this client server architecture. 这种客户端-服务器架构。 76:42 There's always, in that circumstance, somebody right 在这种情况下，总会有一个人 76:45 in the middle that basically owns, updates, governs that whole architecture. 在中间基本上拥有、更新、管理整个架构。 76:54 My business judgment on this is if you're 我对此的商业判断是，如果你在 76:59 moving things of value, you want those things to value 转移有价值的东西时，你希望这些东西的价值 77:03 to have some final settlement and immutability. 有一些最终的结算和不可变性。 77:08 And immutability append-only logs give you some of that final settlement. 而不可变的追加日志为你提供了一些最终的结算。 77:13 We talked very briefly about a lawsuit 我们简要谈到了一个诉讼 77:15 that was 300 plus years ago-- the Crawford case in Scotland 这是300多年前的——苏格兰的克劳福德案 77:19 that you won't have to remember. 你不需要记住这个案子。 77:22 But this-- watch this. 但是这个——看这个。 77:25 So steal this from me. 所以从我这里偷走这个。 77:27 Just do me a favor. 帮我一个忙。 77:28 Just steal it. 就偷走它。 77:29 OK. 好的。 77:29 Right now, I have a right of action. 现在，我有一个诉权。 77:31 But if you give it to-- who are you going to give it to? 但如果你把它给——你会给谁？ 77:34 I don't have any rights against you. 我对你没有任何权利。 77:37 No. 没有。 77:38 Well, wait. 等一下。 77:39 It depends whether he knew you stole it from me. 这取决于他是否知道你是从我这里偷的。 77:42 But it's gone. 但它已经不见了。 77:45 That's final settlement. 这就是最终的结算。 77:47 Those $2 are gone. 那两美元已经不见了。 77:50 That's final settlement. 这就是最终的结算。 77:51 It's immutable. 它是不可变的。 77:52 I can't get them back. 我无法找回它们。 77:54 What, Christopher? 怎么了，克里斯托弗？ 77:55 You want them? 你想要它们吗？ 77:55 AUDIENCE: I just was asking for the money. 观众：我只是问问钱的事。 77:57 PROFESSOR: You were asking for the money. 教授：你在问钱的事。 77:59 I just use that as a visualization. 我只是用这个作为一个可视化的例子。 78:02 Money is a social consensus and a social construct. 货币是一种社会共识和社会构建。 78:06 But if you think of it in terms of ledgers-- look, the money's gone. 但如果你从账本的角度来看——看，钱已经不见了。 78:09 I can't get it. 我无法找回它。 78:10 That's it, you know? 就是这样，你知道吗？ 78:12 That's good. 这很好。 78:13 You all go to Sloan, I can tell. 我能看出来你们都在斯隆学习。 78:16 Yeah, yeah. 是的，是的。 78:18 But it's an important concept. 但这是一个重要的概念。 78:20 I think of this whole that way. 我就是这样看待整个事情的。 78:22 So there were two questions, and then we'll-- 所以有两个问题，然后我们会—— 78:24 and then this is the decentralized end. 然后这是去中心化的部分。 78:27 Bitcoin and Ethereum are kind of at the decentralized end. 比特币和以太坊在去中心化的端点。 78:30 I would contend Bitcoin's more decentralized than Ethereum. 我认为比特币比以太坊更去中心化。 78:34 And centralized databases-- initial coin offerings 而中心化数据库——初始代币发行 78:37 that we'll talk about later, I think, are actually maybe a little bit more 我们稍后会讨论的，我认为实际上可能更 78:40 centralized, even, than permissioned blockchains. 中心化，甚至比许可区块链更中心化。 78:42 But we'll get to that. 但我们会谈到这一点。 78:45 AUDIENCE: No, mine was already answered. 观众：不，我的问题已经回答了。 78:46 And then the other comment was more about the supply chain link. 然后另一个评论更多是关于供应链的链接。 78:49 When you think about the millions and millions 当你想到数百万 78:51 of dollars, the element of transparency 美元时，透明度的因素 78:54 that blockchain kind of brings in to all the parties 区块链为所有参与方带来的 78:56 probably saves an insane amount of money 可能节省了大量资金 78:59 to what you're talking about kind of reconciling all the databases. 用于你所说的对所有数据库进行对账。 79:04 PROFESSOR: So we're going to talk 教授：所以我们将要讨论 79:08 about finance next Thursday and some of the strengths 关于金融的内容，下周四我们将讨论一些优势 79:12 and weaknesses in finance, and some of the attributes, 和金融中的弱点，以及一些属性， 79:14 and you know, one of the readings-- Sheila Bair-- and there's a bunch 你知道，其中一篇阅读材料——希拉·贝尔——还有一堆 79:17 of optional readings about what's 关于金融危机后发生的事情的可选阅读材料。 79:20 happened after the financial crisis and so forth. 79:23 And then we're going to talk about the economics. 然后我们将讨论经济学。 79:25 But I've had three or four groups come in already talking 但我已经有三四个小组进来讨论过 79:28 about the final projects. 关于最终项目。 79:30 So I'll just say, think about whatever you're working 所以我想说，考虑一下你正在做的任何事情 79:32 on as this new technology-- blockchain-- 作为这项新技术——区块链—— 79:35 whether it's permissioned or permissionless-- 无论是有权限的还是无权限的—— 79:38 either one-- does this new technology really address some 无论哪种——这项新技术是否真的解决了某些 79:42 pain point that you're trying to solve, whether it's about payment systems or-- 你试图解决的痛点，无论是关于支付系统还是—— 79:50 actually, there's a group that's talking about doing supply chain on wine. 实际上，有一个小组在讨论如何在葡萄酒上做供应链。 79:55 And I figured, why not? 我想，为什么不呢？ 79:56 I'll probably approve it. 我可能会批准它。 80:01 But it's, what is the pain point that you're actually trying to solve? 但问题是，你实际上想要解决的痛点是什么？ 80:07 Or will decentralized peer to peer networking 或者去中心化的点对点网络 80:11 somehow create a business opportunity in a new model? 是否会以某种方式在新模型中创造商业机会？ 80:15 It might not be a pain point. 这可能不是一个痛点。 80:16 It might be a business opportunity that decentralized systems solve. 这可能是去中心化系统解决的商业机会。 80:22 Or it might be an opportunity that token economics can help solve. 或者这可能是代币经济学可以帮助解决的机会。 80:27 But if there's no pain point you're solving, 但如果没有你正在解决的痛点， 80:30 no token economics, no decentralization peer to peer, 没有代币经济学，没有去中心化的点对点， 80:36 I ask you to use your critical reasoning 我请你运用你的批判性思维 80:38 and move to the next use case, because this is really 并转向下一个用例，因为这实际上是 80:41 about-- this is a business class. 关于——这是一门商业课程。 80:44 This is about finding places for this incredible set 这关乎为这一组令人难以置信的 80:47 of new technologies in the context of markets 新技术在市场背景下找到位置 80:52 and to have a really healthy sense of ground truth about what's possible. 并对可能的现实有一个健康的认识。 81:00 If not, traditional databases. 如果没有，就使用传统数据库。 81:02 Move on. 继续前进。 81:03 I'm not looking for projects at the end 我不希望在学期结束时看到 81:05 of the semester that are using traditional databases. 使用传统数据库的项目。 81:09 It's got to really use blockchain. 它必须真正使用区块链。 81:12 So I thank you. 所以谢谢你。 81:13 I'll see you next Thursday. 下周四见。