 The book is Mastering Bitcoin. It was published December 11th. It came out on paper, immortalizing all of the mistakes of the first edition, and fixing them in a printable, hard, medium, and to my eternal shame. This book is full of mistakes. Now, if you're a programmer, you understand why that is. We're dealing with software, and this is a moving target. Many things in Bitcoin changed day-to-day. Many of the things in this book were wrong the moment they were written. Some of the things in this book were correct at first, and then they became wrong over time. What I'd like to do is extend a challenge and an invitation to all of you. Find all of the mistakes in the book, and then do a poll request. GitHub, Bitcoin Book, the entire thing is open source. It's available under Creative Commons license. It's free to read. It's free to mash up. It's free to reuse. You don't really need the Dead Trees edition. All this guarantees that it's already out of date by the time the first print happens. But I would love it if you could find these little mistakes and let me know, and do a poll request. And in the spirit of open source, I will incorporate that and fix the mistakes, and the next edition is going to be printed. As soon as it hits paper, it will be full of mistakes again. Then we repeat that process in a process of continual evolution and development. Software gets better over time, and bugs are shallow. The more eyes that see them. This is the open-source concept in a book. O'Reilly, fortunately, is a publisher who is very comfortable with this concept. They have been very supportive both in developing this in a community fashion, but also in accepting changes. I look forward to hearing if you can find all of the things that are wrong about this book. However, many things are correct in this book. Hopefully you will find that it does give you some useful information. I have tried to make it accessible to all types of people who are involved in Bitcoin. The first two chapters are pretty readable for someone who is technically minded, but not necessarily a developer. You don't need to write a word of code in order to read the first couple of chapters. It starts getting hairy after chapter four. It starts getting a bit more complex. Hopefully you will find that it conveys some good analogies on some of the key structures in Bitcoin. I was doing a book giveaway the other day, and wanted to do some kind of competition, ask a question, and see who would get the right book. I asked those roomful people, and they said, okay, who knows what a bloom filter is in here? Who knows what a merkle tree is? Oh, fantastic. None of you need this book. The people who didn't raise their hand get a free book. That is how I run the competition. After all, if you already know what these things are, you don't really need to read it. I want to talk very briefly before we go. We are going to do a book signing. Everybody gets a book. I will be happy to sign the book, any dedication you want. If you just come up and don't say anything, the default will be two, the name that is on your badge, and my signature. If you want me to write something else, almost anything is acceptable. I will write it on the book. If you want to donate it to someone else under a different name, for example. I want to talk about the difference between programmable money and institutional money. I don't really prepare my talks. I kind of ad hoc and improvise, but this came from a tweet I received this morning. Someone said, you know, there is a lot of talk among those who are opposed to Bitcoin about the fact that it has irreversible transactions. And how that is a major weakness of the system, irreversible transactions. I thought that was really, really interesting. The reason it is interesting is because it shows a fundamental misunderstanding of what we are doing here, and what this technology is really about. Because irreversible transactions, to point that out as a problem in Bitcoin, is to take one of Bitcoin's biggest strengths... and to think it is a weakness. One of the funny things that happens with Bitcoin is that it gives us a hard core of trust, the decentralized trust model. That trust is hard. From that hard core of trust, you can extend and create guarantees. Guarantees of performance, verifiability, security, and in the case of transactions, irreversibility. Irreversibility is a feature that derives directly from the hard core of trust. If you think about it as programmable money, then you realize, from this hard core of trust, you can then add layers of innovation that soften that guarantee if you want. As a developer, I look at that technology and think, well, actually making reversible transactions in Bitcoin isn't difficult. You can simulate it very, very easily. Let me give you a simple example. You could use a multi-sig transaction between a buyer and a seller, and then have that transaction presign a payment to the seller with an unlock-time-delayed guarantee. You do automated escrow. Money goes into escrow for 30 days, 14 days. What do credit cards do as chargeback? Pick a number. You can do a delayed transaction. The seller knows that 30 days after, they have a preside guaranteed verified transaction with an unlock-time that can verify it independently. That means that you have the money, and in 30 days it will be theirs. But if something goes wrong with a transaction, you can use a third-party arbitration escrow agent, who is holding the third key, to dispute that transaction, issue a countervailing transaction that double-spends the inputs, and refund the buyer because the product wasn't delivered. The product was faulty. With just a combination of two of the most common technologies in Bitcoin and the use of a third-party escrow, I have taken the hard-core promise trust of irreversible transactions, and I have softened it programmatically, and created a fully reversible automated escrow chargeback capability that offers consumer protection as a software service. But yet, in this model, the market for arbitration is open to everyone, not just Visa. For example, if you are on the Visa network, you have to do Visa rules for escrow and chargeback in arbitration. If you are on the PayPal network, you have to use PayPal's rules, but on the Bitcoin network, you can pick your own arbitration provider. Now we have programmatically simulated consumer protection with a brand-new open market for arbitration services. Plus, I still have the underlying guarantee that, in thirty days, that lock-time transaction will execute, and will be verified unless there is a countervailing spend. So I took irreversible transactions of core, softened it, and created reversible transactions. Guess what banks can't do? They can't simulate an irreversible transaction. You can't take a soft and fuzzy infrastructure full of counterparty risk and intermediaries, and simulate hard trust. They can't do irreversible, but if you start with irreversible, programming a soft simulated reversible transaction is easy. It's just a matter of adding a layer. See how what they see as a flaw is actually a great strength, because we are taking a fundamental feature of hard trust, and then we are programming different layers around it. The same thing applies to counterparty and institutional trust. Institutional money is built around a soft layer full of counterparty risks. It can't innovate fast, it can't deliver trusted services, it can't deliver hard, trusted models, and it can't change. The reason it can't change is because in order to change institutional money, you have to orchestrate all of the different layers. It's not just the Visa API, but every single counterparty and intermediary that's in there. The network itself has all the intelligence in the center. Bitcoin is the exact opposite. It offers a very simple, primitive core, which has a hard trust model, and then all of the intelligence is pushed to the edge, allowing innovators like the people in this room to create innovation without permission, to add innovation layers at the edge, to implement applications, services, products, financial instruments that redefine the trust model, and to do so they don't have to ask for anyone's permission, write and deploy. That is the fundamental difference between programmable money and institutional money. It still strikes me as highly ironic how the people who criticize Bitcoin for some of its greatest strengths have not figured out yet that there is no way in the world they could even begin to simulate these strengths. Yet, we can simulate their mushiness all day long, in software, easy peasy. We can implement the things, and they criticize Bitcoin for exhibiting the characteristics of a toddler currency, which is exactly what Bitcoin is. It's only five years old. Already, we're reinventing financial services that took hundreds of years to build on the counterparty model. We're moving faster and faster as this pace is accelerating. That's my little spiel based on just a tweet I got this morning. I thought it would be interesting to look at the difference between programmable money and institutional money. Thank you so much for coming. We'll be doing a book signing outside if you could. Let me know. Everybody gets a free book, and I hope to see you again at the MIT Bitcoin meet-up if you choose to come. Thank you.