cryptologie.net

I get the same email often enough (“hey, we’re shipping some crypto, who do we talk to?”)

In 2022, Vitalik floated the idea of “soulbound NFTs”, NFTs that would be linked to your identity forever.

It was six years ago, when I joined the security team of Libra/Diem at Facebook.

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.

I wrote about Bulletproofs / inner product arguments (IPA) here in the past, but let me try again.

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 Transactions and More.

I was a bit frustrated with the look of this website.

I recently installed all the agent CLIs I could find (basically anthropic claude code, openAI codex CLI, and Google gemini CLI).

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.

Here’s a short note on the Montgomery reduction algorithm, which we explained in this audit report of p256.

By now there’s already a number of great explanation for Plonk’s permutation argument (e.g. my own here, zcash’s).

I already wrote about the linearization technique of plonk here and here.

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 that in a short amount of time.

Check out https://blog.zksecurity.xyz/posts/internship-2025/ Looking for an internship in ZK, MPC, FHE, and post-quantum cryptography?

I tried to record a few short videos these last months (eventhough the last one is quite long).

If you have missed me, I was in different places on the Internet and in real life.

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.

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!