Jack Lloyd
Vermont, United States
Summary
🤩
RockstarJack Lloyd is a senior software engineer with 20 years of experience building secure, reliable systems deployed in banks, vehicles, intelligence agencies, ISPs and IoT devices. He specializes in cryptography and backend engineering, contributing to high-profile open-source projects like the Botan crypto toolkit and Google’s OSS-Fuzz to harden and fuzz large codebases. At DFINITY he works on threshold ECDSA and zero-knowledge proof components for the Internet Computer, blending rigorous cryptographic engineering with practical production concerns. His background includes signal-messaging, secure enclaves, trading systems and consulting, giving him deep experience across security-sensitive and high-performance domains. Based in Montpelier, Vermont, he combines hands-on implementation (including avoiding raw pointers and optimizing hash‑to‑curve operations) with build-automation expertise that improves long-term robustness and testability.
20 years of coding experience
Stackoverflow
8,315reputation
895kreached
101answers
12questions
html
top-5%
base64
top-5%
security
top-5%
cryptography
top-1%
validation
top-5%
image
top-5%
Github Skills (30)
c-language10
tls1210
bash10
tls1310
security10
mtls10
cryptography10
build-automation10
blockchain10
libtls10
fuzzing10
rust10
cprogramming-language10
fuzzer10
fuzz-testing10
Programming languages (22)
Github contributions (5)
randombit/botan
May 2006 - Jan 2023
Cryptography Toolkit
Role in this project:
Back-end Developer & Security Engineer
Back-end Developer & Security EngineerContributions:1460 reviews, 12552 commits, 4256 PRs in 16 years 11 months
Contributions summary:Jack implemented and improved security features related to cryptographic toolkit functionality, specifically focusing on Elliptic Curve Cryptography (ECKCDSA) with hash truncation, and the implementation of key agreement. Their contributions included bug fixes, updates for the TLS implementation, and improving the robustness of the code. The user also refactored some code to avoid raw pointers.
cryptographycryptocryptography-librarytlsx509
dfinity/ic
Nov 2021 - Jan 2023
Internet Computer blockchain source: the client/replica software run by nodes
Role in this project:Back-end Developer & Cryptography Engineer
Back-end Developer & Cryptography EngineerContributions:229 reviews, 227 commits, 115 PRs in 1 year 2 months
Contributions summary:Jack contributed to the development and maintenance of the Internet Computer blockchain's core cryptographic components, focusing on the Threshold ECDSA (tECDSA) implementation. Their work primarily involved enhancing the cryptographic library by adding tests, optimizing the hash to curve operations, and implementing zero-knowledge proofs related to MEGa encryption. The user also implemented critical functionality related to creating, verifying, and combining digital signatures and contributed to building the robust functionality needed to create and manage the digital signatures for the system.
blockchain
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.