Cryptography, Security, and Programming
I get the same email often enough (“hey, we’re shipping some crypto, who do we talk to?”) that I figured I’d just write the answer down once. So here’s the answer: if...
In 2022, Vitalik floated the idea of “soulbound NFTs”, NFTs that would be linked to your identity forever. Today, with zkML (which I’ll explain in a bit), I think we can go further:...
It was six years ago, when I joined the security team of Libra/Diem at Facebook. Two years later I was security lead and I had learned a huge number of lessons, some even life lessons. I’ve...
I recorded a short vlog on how to get “in the zone”
And here is the second part of this video, going over the Dalek explanation of how range proofs on top of bulletproofs work.
Today I want to showcase something really cute that zcash’s halo2 implementation has designed in order to implement Fiat-Shamir in a secure way. If you take a look at their plonk prover, you...
I wrote about Bulletproofs / inner product arguments (IPA) here in the past, but let me try again. The Bulletproofs protocol allows you to produce these zero-knowledge proofs based only on some...
In this video I quickly go over the amazing post from the dalek implementation of bulletproof, which itself goes over the range proof protocol of Bulletproofs: Short Proofs for Confidential...
I was a bit frustrated with the look of this website. In spite of people complimenting it a lot over the years, it felt like it had badly aged. I’ve also slowly converted my dynamic websites...
I recently installed all the agent CLIs I could find (basically anthropic claude code, openAI codex CLI, and Google gemini CLI). I admit that I wasn’t expecting much at first, but it...
I’ve talked about iterative constraint systems in the past, which I really like as an abstraction to build interactive (and then non-interactive) proof systems. But I didn’t really...
Here’s a short note on the Montgomery reduction algorithm, which we explained in this audit report of p256. If you don’t know, this is an algorithm that is used to perform modular...
By now there’s already a number of great explanation for Plonk’s permutation argument (e.g. my own here, zcash’s). But if it still causes you trouble, maybe read this visual...
I already wrote about the linearization technique of plonk here and here. But there’s a more generalized and high-level view to understand it, as it’s being used in many protocols (e.g....
As a security consultant you’re most of the time forced to do something that no developers do: you’re forced to become an expert in a codebase without writing a single line of code, and...
Check out https://blog.zksecurity.xyz/posts/internship-2025/
I tried to record a few short videos these last months (eventhough the last one is quite long). You might enjoy some of them:
If you have missed me, I was in different places on the Internet and in real life. Here are three whiteboard sessions on different aspects of zero-knowledge:
Years ago, naive me lost a lot of money because he was too stingy to hire a financial advisor, and too lazy to do some basic research. Hopefully you don’t make the same mistakes. It took me a...
I guess I don’t post that much about the startup I cofounded more than a year ago, so this is a good opportunity to release a short note for the curious people who read this blog! I posted a...