Post-Doctoral Researcher, Cornell University
How quickly can Secure Distributed Computer Systems operate?
The ubiquitous nature of computer systems means that they often operate in hostile environments where they are subjected to various attacks by adversarial parties. The purpose of such attacks often varies, ranging from simply corrupting the system’s behavior to a complete extraction of otherwise unavailable, secret information.
Secure Multi-Party Computation (MPC) is a fundamental primitive in the study of modern cryptography that facilitates building secure distributed computer systems for private data in hostile environments while providing the strongest form of security. In more detail, MPC allows a set of mutually distrustful parties to compute a function jointly over their inputs while maintaining the privacy of the inputs and ensuring the correctness of the outputs. Assuming the existence of a trusted third party, a trust-based solution can be given where the trusted party receives inputs from all the parties, computes the function and returns the result. However, this is rather unsatisfying from a security perspective, if not outright unrealistic. Surprisingly, seminal results established in the ’80s, show us that the parties can compute the result with the same level of security that the trusted entity provides via a cryptographic protocol assuming no trusted entity. There are countless applications of MPC such as electronic auctions, secure signal processing, distributed ledgers as in block-chain technologies, HIPAA compliance health-care or genomic data-mining, to name just a few.
Even though the efficiency of MPC protocols has been significantly improved in recent years, we are still far from being able to apply MPC to large-scale computations. That said, my research focuses on the following main question: How quickly can secure MPC systems operate? To this end, my research has established communication complexity ( i.e., the number of transmitted bits in a protocol execution) limitations of MPC protocols under the best security guarantees.
Antigoni Polychroniadou is currently a post-doctoral researcher at Cornell University (Cornell NYC Tech campus), hosted by Rafael Pass, Elaine Shi and Muthu Venkitasubramaniam. Her research interests lie in cryptography and more broadly in theoretical computer science.
Polychroniadou completed her Ph.D. at Aarhus University in the Crypto Group, under the supervision of Ivan Damgård. She holds an M.Sc. in Mathematics of Cryptography and Communications from Royal Holloway University of London, where she was advised by Kenny Paterson. She received her B.A. in Computer Science and Economics at the University of Macedonia, Greece under the supervision of George Stephanides.
Polychroniadou has done internships and research visits with Alon Rosen at IDC Herzliya, with Tal Rabin at IBM Research T.J. Watson, with Yuval Ishai at the Technion and with Sanjam Garg at UC Berkeley.