Chalkias co-founded Mysten Labs, the company developing the Sui blockchain, where he serves as the chief cryptographer, leading research in applied cryptography.

Chalkias completed his PhD in Security and Cryptography from the University of Macedonia, following his BSc in Applied Informatics (2004) and MSc in Computer Systems (2006).

He joined R3 in London as lead cryptographer and blockchain engineer, contributing to the Corda blockchain with work on zero-knowledge proofs, post-quantum signatures, and secure enclaves.

He became the lead cryptographer at Meta, working on cryptographic research for the Diem blockchain, Novi wallet, and WhatsApp, developing protocols like proof-of-solvency systems.