Overview

My work centers on blockchain custody, signing and key management, and security engineering.

Specialized Expertise

Blockchain Custody & Chain Integration

I own core custody integrations at a regulated custodian securing billions in assets. I built the full Bitcoin UTXO lifecycle (selection, PSBT, SegWit, reorg detection, dynamic fees) and a generic Ethereum transaction-execution engine and the ETH staking lifecycle across the pre- and post-Pectra upgrades, and I am the sole owner of all Cosmos integrations (6 chains). I designed Solana's integration architecture and maintain several other L1s — 10+ integrated in production.

Signing & Key Management

I operate the full custody signing flow: intent verification, on-chain enrichment, HSM-backed signing, and broadcast. I contributed to the HSM implementation and maintain the pipeline, grounded in elliptic-curve cryptography (secp256k1) and ECDSA/EdDSA, with a strong command of threshold-signature schemes (FROST, CGGMP21) and MPC/TSS custody architectures.

Security Engineering

I build and ship security tooling as open source: Keygrain, a stateless password manager built on Argon2id and HMAC-SHA256, and Mailcheck, an email-security analysis platform. Both use standard cryptographic primitives and are backed by extensive automated testing.

Technical Skills

Custody & Key Management

HSM integration & lifecycle
Signing-pipeline architecture
M-of-N authorization policies
Dual-control / four-eyes approvals
Transaction construction & broadcast
Shamir's Secret Sharing
Threshold signatures (FROST, CGGMP21)
MPC/TSS architectures
PSBT workflows

Blockchain Protocols

Bitcoin (UTXO, SegWit, PSBT, Script)
Ethereum (ERC-20, EIP-1559, staking pre/post-Pectra, BLS validator keys, bespoke TX execution)
Cosmos SDK (staking, chain modules)
Solana (SPL)
Substrate / Polkadot (incl. Centrifuge)
Near
Mina
Flow
Oasis

Languages & Systems

Golang
C++ (17/14/11)
C
Python
Solidity (reading)
Shell
Embedded Linux

Infrastructure & Tooling

Docker
CI/CD
gRPC
REST API design
PostgreSQL
Git
GDB
Performance profiling

Security & Cryptography

Elliptic-curve cryptography (secp256k1)
ECDSA / EdDSA
Argon2id
HMAC-SHA256
AES-256-GCM
Secure development lifecycle

Spoken Languages

Arabic (Native)
English (Fluent)
French (Fluent)
German (Beginner)