Look inside my upcoming book, Defending Bitcoin: Industrial-Grade Cybersecurity for the Monetary Grid 👇 First, the Foreword by Mikko Hyppönen. One of the most widely-respected figures in cybersecurity with his own take on Bitcoin. I'm grateful that he agreed to contribute his view to the Defending Bitcoin! Next the Introduction. My story of how I started in the Industrial Controls sector, then found Bitcoin, and merged the two worlds. Also goes over the format of Defending Bitcoin. Part I is the introduction to Bitcoin and Cybersecurity, forming a basis of vocabulary for readers familiar with either or neither subject. Chapter 1. Bitcoin — The Decentralized Protocol All about Bitcoin the technology, written for technically-minded readers who don't know about how Bitcoin works. Chapter 2. Bitcoin — The Hardest Money Ever Made All about Bitcoin the money. What makes Bitcoin's monetary properties different from every other money in history. Chapter 3. Cybersecurity Fundamentals — The Universal Shield The vocabulary of cybersecurity based on industry best practices. What is risk, what are threats, vulnerabilities, controls. Everything we need for the rest of the book. Chapter 4. Industrial Control Systems and Securing Critical Infrastructure How critical infrastructure is defended differently from traditional cybersecurity. Includes a primer on industrial control systems and critical infrastructure so my the comparison to Bitcoin makes sense. Chapter 5. Bitcoin as Critical Infrastructure — The Monetary Grid The core thesis, that Bitcoin is the first decentralized critical infrastructure for money and should be defended the same way we protect power grids, pipelines, and factories. Part II is the Bitcoin Threat Landscape. 10 chapters of threats on an individual and network level, and what we can do about them. Chapter 6. Exchange and Custodial Failures From Mt. Gox to FTX, why custodial Bitcoin keeps blowing up, and what that means for your stack. Hint: the answer is to get your Bitcoin off the exchanges and into self-custody. Chapter 7. Securing Your Bitcoin: Personal Defense of the Private Key The full personal custody chapter, covering hardware wallets, multisig, seed phrase handling, and inheritance. You have the responsibility to secure your Bitcoin. Learn how here. Chapter 8. Privacy, Physical Security, and Staying Safe Privacy on-chain, OPSEC off-chain, and maintaining your physical security when people know you own Bitcoin. Huge shoutout to the excellent Praxeology of Privacy by @Max , read that after this chapter. Chapter 9. 51% Attacks and the Decentralization of Mining What a 51% attack would actually look like, why mining concentration is important, and how decentralized the hashrate really is. Includes practical steps to do something about it, as always. Chapter 10. Node-Level Threats and Client-Side Defenses Everything to do with the security of your node, including all the work being done to secure Bitcoin node software, and what they defend against. Run a node, stay secure while you do. Chapter 11. Arbitrary Data and Witness Abuse An overview of ordinals, inscriptions, and arbitrary data. You may not think these are a problem. I lay out why it's a cybersecurity issue and makes Bitcoin worse as money. Chapter 12. Governance Risks. An honest examination of the risks Bitcoin faces from development centralization, and what can be done about it. It's not one-sided, though. I also cover the risk of changing Bitcoin, especially without wide consensus. Chapter 13. Political and Regulatory Threats Bans, surveillance, KYC, and mining restrictions, plus the realistic ways Bitcoin survives state-level pressure. Chapter 14. Grid and Network Failures: Keeping Bitcoin Alive Offline What happens when the grid goes down or the internet gets cut, and how Bitcoin stays alive offline through mesh networks, radio, and satellite. Chapter 15. Emerging Threats: Quantum and AI Full coverage of the latest developments of Bitcoin and Quantum. No FUD, but it's not something we should ignore. Also includes coverage of AI as it affects everyone more and more these days. Conclusion We end summarizing everything together, and it's optimistic! Defending Bitcoin isn't about doom and gloom. It's about knowing what's out there, and finding out what you can do about it. There's always something you can do. Always. Appendices Included in the print book are glossaries of cybersecurity and Bitcoin terms, and a section of recommended reading across all topics. Further resources are available on defendingbitcoin.com, including a threat model worksheet where you can find out how the threats in Defending Bitcoin apply to you. No data collection, I promise! You can see more about the book at the Look Inside page, including the full foreword, introduction, and previews from two chapters.

Look inside: Defending Bitcoin

Full table of contents, with foreword, personal introduction, openings of Chapter 5 and Chapter 7, and the conclusion expandable in place.

Reminder, Defending Bitcoin will be available on Amazon and bitcoininfinitystore.com from June 15th, and the first physical copies will be available at @BTC Prague - come see me there and get a signed copy!

I've been a bit absent from Nostr for the last little while, but that's about to change. For the past few months, I started focusing on a new project, and I'm finally ready to announce what I've been up to. I've written a book. Defending Bitcoin: Industrial-Grade Cybersecurity for the Monetary Grid. 6 months ago, I realized how I could apply my cybersecurity background to Bitcoin, with a perspective grounded in the world of critical infrastructure and industrial control systems. In Defending Bitcoin, I make the case that Bitcoin is critical infrastructure, and I mean that technically. Critical infrastructure is everything essential for the modern world to run the way it does, and I assert that Bitcoin meets the threshold of that definition. Defending Bitcoin is grounded in the industrial cybersecurity principles that I use on a daily basis. The framework I've built is based on ISA/IEC 62443, the most widespread industry standard for industrial cybersecurity, and applies universal cybersecurity principles such as defense-in-depth, risk management, and threat modeling. And in all cases, there's always something you can do to improve your security or that of the network as a whole. I wrote the book for two audiences at once. The first is bitcoiners who want to improve their security posture. The second is technical professionals who may be skeptical about Bitcoin and want to understand it better. I build a base of vocabulary for both sides to understand each other, then cover the threat landscape over the course of 10 chapters. Launching today is the accompanying website,

Defending Bitcoin

Defending Bitcoin — Luke de Wolf

Industrial-grade cybersecurity for the world’s first decentralized monetary network. A book by Luke de Wolf, with a foreword by Mikko Hyppönen.

where you can get a preview of the book, read endorsements from Mikko Hyppönen (the foreword writer), @Jeff Booth , @Lyn Alden , @npub1d3f4...r4xv , @Max , and @Tony | thebitcoinway.com . I've also built a threat modeling tool where you can check how the book applies to you (fully local, we don't collect any data except your email address, if you want updates). Defending Bitcoin will be available for purchase online on June 15th, right after @BTC Prague where I'll be debuting the book physically. Use code DEFENDINGBITCOIN for your ticket, and come see me in Prague to get your signed copy! I'm thrilled to be releasing this book because it's truly the best possible contribution to the space that I can make. I managed to find a way to bridge the two worlds I live in, those of my day job in cybersecurity and Bitcoin. I hope you find the book to be a helpful guide to improving your security, and that it makes a positive impact for Bitcoin as a whole. I'll be posting more often about the Bitcoin cybersecurity topic, and hopefully that's valuable as well. I'm looking forward to hearing what you think!

What exactly is censorship on Bitcoin? Here's my answer: certain addresses being blocked on consensus level. Changes to policy to limit specific forms of transaction is not censorship, it's discrimination. I'll explain what I mean by that. Bitcoin has always discriminated in terms of what can go into a transaction. It has never been possible to put whatever you want into a transaction, just like it's never been possible to double spend a UTXO. I'm glossing over a ton of minutiae here, for simplicity. The previously agreed amount of data that is allowed in a transaction has been set to a reasonable level, through OP_RETURN. There have been disagreements as to that level, but even the most permissive amount was 80 bytes of data in practice. This has been more than enough, and it has been enforced by policy, not consensus. Since SegWit and Taproot, more ways to put arbitrary data (spam) on chain have been discovered. That is to say, the ability to do these things was right there, as unintended consequences of development changes. Uncaught bugs, or a lack of forethought about human behavior. Filters on the policy level have been ineffective in containing spam. However, they have provided individuals who are against spam with tools to control their own nodes and mined blocks. Individual policy choices are a form of discrimination, not censorship. Discriminating against certain types of consensus-valid transactions is perfectly fine. I even go so far as to say that discriminating against transactions from certain address is also completely fine. These are all individual choices. Every individual on the network is free to make those choices. Anything short of that is coercion. Consensus rules, on the other hand, are where censorship is possible. This is where it would be possible to block certain addresses from moving their UTXOs. As I understand it, this is usually termed confiscation. In practice, this would likely be the result of making some technical type of coin unspendable. In theory, some list of addresses could be drawn up that says they can never move their coins. Good luck getting that adopted. Consensus changes that do not prevent certain addresses from moving their UTXOs are not censorship. Making it so that transactions containing arbitrary data invalid is not censorship. Making those transactions more expensive is not censorship. Private key holders will still be perfectly able to move their UTXOs. They can even add some arbitrary data through OP_RETURN, or jump hoops (and pay fees) to encode their data some other way. This is discrimination against certain types of transactions. Those which have no intention of using Bitcoin as money, or which misuse the network for their own purposes (I use the word misuse here to mean that they are using exploits which were not intentional developments). If the majority of the network decides to eliminate the possibility of those transactions in the future, that is not censorship. And, as previously mentioned, that has not been effective on a policy level. The consensus level is all that is left. I'm not going to discuss the currently proposed soft fork in extensive detail, except to say that I think the proposal is technically extremely reasonable in my understanding. Compromises have been made to allow for other specific potentially useful data types by consensus. The language about legal consequences is completely unnecessary, and I hope it is removed. I hope this proposal or a similar one passes. Bitcoin is money, not data storage. To hammer these points further: I might morally object to some miner rejecting transactions from specific addresses, but I can't do anything to force them to include those transactions in blocks they mine. I can put public pressure on them to change their view, but I can't force them to do so. This would still not be censorship. All individuals on the network are free to do what they want, including rejecting transactions they disagree with. Here's the beautiful thing: we're not all the same! One miner might reject some transactions. Another one almost certainly will include those transactions. This is primarily why filters don't "work" - someone will always mine valid transactions. I still support filters on the node level. Nobody can force me to include transactions I don't want in my mempool. In other words: as long as the consensus is not making it impossible for certain addresses to move their coins, it's not censorship. Discriminating against certain types of transactions or certain arrangements of arbitrary data is not censorship. Everyone on the network is still free to move their UTXOs. Bitcoin is useful as money. The best money. That's the important thing. What do you think?

GM Nostr! I'm back after a bit of a self-enforced social media hiatus. It was Nostr, Twitter, everything. I was more than a little burnt out after BTC HEL. I didn't really get a proper break after the conference, since I went straight back to my fiat job the next day. All I had energy for was keeping the lights on at @Bitcoin Infinity Media . I was also more than a little shaken up by Charlie Kirk's death. I won't say much more about that here, but the TLDR is I did a lot of thinking about the risks of being public and saying controversial things. I was strongly considering taking a big step back from the space. Nope! I'm back, and ready to get started on new things! I got out to a couple of fantastic conferences, first BTC Balkans in Sofia, Bulgaria, then the Plan B Forum in Lugano. My Bitcoin batteries are fully recharged, even if I was pretty exhausted after a week of conferencing. Reconnecting with old friends and making new connections is what this is all about. I especially enjoyed the Rockamoto in Lugano - I can't believe I get to do all this cool stuff! Thanks @Knut Svanholm ∞/21M , @Sirius , and @Samson Mow for just being awesome! Looking forward to next time! As for me, it's full speed ahead with the Bitcoin Infinity Show and the Bitcoin Infinity Academy! You may have noticed that I took a step back from the Bitcoin Infinity Show - it's just Knut now, at least in front of the camera. I'm still behind the scenes doing all the editing, but I couldn't keep my schedule flexible enough to join the recordings. I miss it, and I plan to change that. And of course, I'm involved in the planning for next year's @BTCHEL 25.-26. SEPTEMBER - stay tuned for all the details about next year's conference, and don't hesitate to reach out if you want to speak! Thanks everyone for making this community amazing. I'm full of gratitude, and I can't wait for what's in store ahead.

I can't believe how anyone can suggest without a hint of irony or sarcasm that you have to contribute to a specific open source project in order to have an opinion about Bitcoin. This is simultaneously elitist and mind-bogglingly stupid. It's correct that Bitcoin Core is an important part of the Bitcoin technology stack, but it isn't the only client available, which is a good thing. Being able to understand the code of Bitcoin Core gives you the ability to do exactly one thing: understand the code of Bitcoin Core. It says absolutely nothing about your ability to understand the implications of changes to the system, of what users want, or the purpose of Bitcoin itself, for that matter. Bitcoin Core developers are developing a product, and their customers are the users of the Bitcoin network. The Core developers don't get to dictate what the users are supposed to think. It's entirely the other way around. If the users don't like something Core plans to do, Core shouldn't make the change. Core ignored its users, so now they're getting fired, by users switching to an alternate client.

Bitcoin is as much an idea as it is a technology. Bitcoin adoption doesn't happen because the code is impeccable. Bitcoin adoption doesn't happen because the tech is cool. Bitcoin adoption doesn't happen because you can put pictures on a blockchain. Bitcoin adoption happens because it is the best form of money we've ever seen, and because the people who figure that out tell other people about it.