Kostas Chalkias is a cryptographer and co-founder of Mysten Labs, where he serves as the chief cryptographer. In his role, he directs research and development in applied cryptography, with a particular focus on enhancing the security and scalability of the Sui blockchain. ^[1]

Education

Chalkias attended the University of Macedonia, where he completed a Bachelor of Science in Applied Informatics in 2004. He continued his studies at the same institution, earning a Master of Science in Computer Systems in 2006 and a Doctor of Philosophy in Security and Cryptography in 2010. ^[2]

Career

Chalkias's career began in the early 2000s with roles as a web designer and administrator, where he was responsible for developing and managing websites and network infrastructures. In 2003, he joined the technical staff at ELTA Hellenic Post, where he supported logistics and tracking software. He later returned to the University of Macedonia as a lab and teaching assistant, working as a cryptography and security engineer on several research projects from 2006 to 2013. During this time, he also served as an informatics officer and systems administrator for the Hellenic Army Academy, where he conducted training on network security. Concurrently, he contributed to a European Union FP7 project focused on biometric identity systems as a contract cryptography engineer in France.

From 2007 to 2008, Chalkias worked for the Hellenic Telecommunications Organisation, offering technical support for internet services. He also served as a computer science instructor for the Greek Ministry of Education between 2005 and 2008. From 2011 to 2016, he undertook independent cryptography projects under the name NewCrypt, focusing on applied encryption and machine learning. He also co-founded Safemarket Ltd. and Erybo Inc., serving as Chief Technology Officer and overseeing projects related to identity management, fraud detection, and security.

In 2017, Chalkias joined R3 in London as a lead cryptographer and blockchain engineer, where his work on the Corda blockchain included contributions to zero-knowledge proofs, post-quantum signatures, and secure enclaves. He moved to Meta in 2019 as lead cryptographer, conducting research for the Diem blockchain, Novi wallet, and WhatsApp, and developing protocols for range proofs and proof-of-solvency systems. Since 2022, he has served as co-founder and chief cryptographer at Mysten Labs in Palo Alto, California. ^[3]

Interviews

Hidden Powerhouse

In a July 2025 interview on the Just The Metrics podcast, Chalkias discussed Sui's approach to solving technological challenges in areas such as artificial intelligence, privacy, and decentralized data management. He described how a personal hacking incident during his time as an AI researcher led him to the field of cryptocurrency. He pointed to inefficiencies in healthcare data management as an area where a common database, which Sui's blockchain technology could provide, is needed. Chalkias positioned Sui as a coordination layer for a wide range of applications, from healthcare to personal data management, and noted its capacity to improve transaction security and efficiency. He also mentioned developments in robotics and AI integration, as well as the increasing interest from institutional entities in adopting Sui. The conversation concluded with a discussion on the growing necessity for quantum-safe algorithms to ensure long-term digital privacy and security. ^[4]

About Sui

During a June 2025 appearance on the Encrypted podcast, Chalkias detailed advancements in post-quantum cryptography and upcoming developments for the Sui blockchain. He stated that a goal for Sui was to become the first blockchain to adopt post-quantum technologies, thereby improving security and preparing for future regulatory standards. Drawing on his experience at Meta (formerly Facebook), he emphasized the importance of developing systems that safeguard user assets and utilizing technologies like zero-knowledge proofs to ensure transparency for cryptocurrency exchanges. Chalkias also described Sui's object-centric model, which enables faster and parallel transaction processing. He outlined future ambitions, including developing solutions to help users recover access to their crypto assets and using blockchain to expand financial services to unbanked populations while promoting privacy. ^[5]

Apple of Web3

In an April 2025 interview on London Real, Chalkias spoke with host Brian Rose about the technology behind the Sui blockchain. He noted the background of the development team, which includes individuals with experience at major technology firms, and their focus on making blockchain more accessible and secure. He described Sui's technical capabilities, including its high transaction speeds and simplified onboarding processes, which are designed to ease user entry into Web3. Chalkias explained core Web3 concepts, including decentralization, privacy, and ownership, and shared his outlook on Sui's potential applications across various industries. The discussion highlighted the role of innovation and team culture in navigating the evolving blockchain technology landscape. ^[6]

Presentations

Sui Technologies

At Sui Basecamp in May 2025, Chalkias presented on technologies developed for the Sui network. He noted that the concentration of expertise from previous collaborations, including Meta's Libra project, facilitated unique developments in blockchain technology. He detailed several features, including a method for generating native randomness to enhance application functionality, a decentralized data storage protocol, and improved user authentication mechanisms. He also discussed potential use cases in gaming, AI, and secure transactions, highlighting the system's ability to function without internet connectivity, as observed during power outages in Spain and Portugal. Chalkias also touched on the integration of advanced cryptographic methods and future concepts, such as time capsules for secure data encryption, as well as the potential for quantum-safe technology. ^[7]

Emerging Tech

In a separate presentation at Sui Basecamp in May 2025, Chalkias discussed technological concepts from the Sui blockchain, specifically targeting the startup ecosystem. He reiterated that the team's collective knowledge enabled developments such as native randomness, decentralized storage, and secure digital signatures that do not rely on traditional passwords. The presentation covered the applications of artificial intelligence and non-fungible tokens (NFTs) in various sectors, including gaming, communication, and data management. The potential for off-chain transactions, which would enable activities such as gaming or commerce to continue even without an internet connection, was also highlighted. Other concepts introduced included time capsules for secure information sharing and account recovery systems, illustrating Sui's broader technological goals. ^[8]