Applied cryptography · Ho Chi Minh City

Notes and code from building MPC systems.

I work on multi-party computation, threshold signatures, post-quantum cryptography — and, lately, tooling for cryptographic security review. This page collects what I've built and what I've written along the way, mostly so other people building the same things don't have to start from zero.

MPC DKG · secret sharingThreshold DKLS23 · ECDSAZK Plonky2 · Halo2PQC ML-KEM · ML-DSAReview audit tooling
Work
Live

DefiShard

A self-custodial MPC wallet, built end-to-end: cryptographic SDK, relay server, browser extension and mobile app.

2-of-2 DKG · browser-initiated, mobile-approved
Threshold ECDSA, no key ever assembled
defishard.com
Building

Agent Wallet

A signing layer for AI agents: an agent can transact, but never move funds on its own.

2-of-3 · agent, policy engine, human approver
A circuit-breaker for autonomous systems
Write-up coming
Stealth

SecAudit

A platform for cryptographic security review — carrying a design, its code and its findings through one reconciled assessment instead of a PDF per engagement.

Closed pilot · not public yet
Ask me if this is your problem too
Request a look
Notes

Write-ups from the DefiShard build — the cryptography, the engineering, and the parts that went wrong first.

About

Hieu Tran

Ten years turning cryptographic research into systems that ship — MPC, threshold signatures, and increasingly post-quantum. Previously Crossbar, Kyber Network and Incognito; PhD-track at Singapore Management University, with work published at ACM ASIACCS.

Coluy Labs is just the name I put on the things I build outside of work. If something here is useful, wrong, or worth arguing about — I'd like to hear it.

The mark

A bamboo waterwheel from the banks of the Trà Khúc river in Quảng Ngãi — rows of them once lifted water into the fields by turning, holding nothing back.

Contact

If something here is useful, wrong, or worth arguing about — tell me.

hi@coluylabs.org