Centre for Information Security and Cryptography
Scientific study of security systems was pioneered by Claude Shannon using information theoretic approach. In an information-theoretically secure system the attacker has unbounded computing power and security does not rely on unproven assumptions (e.g., factorization is a hard problem) and the guaranteed security will last even with the development of new types of computers, such as quantum computers. The first information-theoretically secure cryptosystem is the one-time pad (due to Shannon) and guarantees perfect secrecy. The One-time-pad requires a secret key of the same length as the message to be securely shared between the sender and the receiver and so is only used in applications that security is of strategic importance. Unconditionally secure systems have been designed for a variety of cryptographic tasks, including message authentication, secret sharing and multiparty computation.
The current focus of our work (though not limited to) is on authenticity of information, deriving information theoretic bounds on performance of authentication systems and construction of optimal and sub-optimal systems achieving the bounds and providing provable security at acceptable cost, respectively. We consider strong attack models such as adversary with oracle access, and new scenarios motivated by recent applications, such as authentication of fuzzy data.