Second Summary Report on Unconditionally Secure Protocols

This report focuses on unconditionally secure cryptographic protocols. Such protocols are based on a limitation of the adversary’s knowledge in an information-theoretic or quantumtheoretic sense. They provide a very strong form of security because they cannot even be attacked by an adversary with unlimited computational resources, in contrast to the notion of computational security used otherwise. We consider three different models that provide unconditional security (noisy-channel cryptography, bounded-storage cryptography, and quantum cryptography), and for each of them we present the current state-of-the-art and stress the most important open problems.