Kostas Chalkias
Co-Founder & Chief Cryptographer at Mysten Labs
San Francisco Bay Area United States
Summary
👤
Senior🎓
Top SchoolKostas Chalkias is a co-founder and Chief Cryptographer at Mysten Labs with over two decades of hands-on experience building cryptographic systems, blockchain security, and big-data platforms. Previously he led cryptography efforts at Meta (Diem/Novi/WhatsApp) and R3, contributing to projects like Winterfell ZKP, Sparse Merkle Trees, EdDSA aggregation and proof-of-solvency standards. He combines deep academic credentials and prolific research—50+ papers, multiple best-paper awards and eight US patents—with startup CTO experience shipping production-grade security and ML systems. Known for practical, high-performance protocols (fast ZK and signature work) and unusual side projects from timed-release encryption to graphical passwords, he blends offensive analysis with defensive engineering. Based in the Bay Area, he also founded Athens’ largest Big Data meetup and remains active in open-source prototyping and cross-disciplinary cryptography research.
12 years of coding experience
13 years of employment as a software developer
Summer School cert, Cryptanalysis, Summer School cert, Cryptanalysis at KU LeuvenInformatics Officer, Computers and Mathematics, Informatics Officer, Computers and Mathematics at School of Research and Informatics Officers of the Hellenic Army (SAEP)BSc, Applied Informatics, BSc, Applied Informatics at University of Macedonia
Github Skills (15)
sdk9
messaging-api8
python7
api7
decrypt6
messaging6
security5
cryptography5
encryption5
backup4
network4
p2p4
communications3
signal3
peer-to-peer3
Programming languages (3)
Github contributions (5)
wfn/torsearch
Jul 2013 - Feb 2016
Contributions:44 commits, 1 push in 2 years 8 months
wfn/tdraw
Mar 2025 - Mar 2025
Draw ASCII art in terminal
Contributions:2 PRs, 2 pushes, 1 branch in 1 day
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