Information Security and Cryptography Research Group

Information-Theoretic Cryptography

Ueli Maurer

Advances in Cryptology — CRYPTO '99, Lecture Notes in Computer Science, Springer-Verlag, vol. 1666, pp. 47–64, Aug 1999.

We discuss several applications of information theory in cryptography, both for unconditional and for computational security. Unconditionally-secure secrecy, authentication, and key agreement are reviewed. It is argued that unconditional security can practically be achieved by exploiting the fact that cryptography takes place in a physical world in which, for instance due to noise, nobody can have complete information about the state of a system.

The general concept of an information-theoretic cryptographic primitive is proposed which covers many previously considered primitives like oblivious transfer, noisy channels, and multi-party computation. Many results in information-theoretic cryptography can be phrased as reductions among such primitives We also propose the concept of a generalized random oracle which answers more general queries than the evaluation of a random function. They have applications in proofs of the computational security of certain cryptographic schemes.

This extended abstract summarizes in an informal and non-technical way some of the material presented in the author's lecture at Crypto '99.

Key words: Information theory, unconditional security, conditional independence, information-theoretic primitive, generalized random oracle.

BibTeX Citation

@inproceedings{Maurer99,
author       = {Ueli Maurer},
title        = {Information-Theoretic Cryptography},
editor       = {Michael Wiener},
booktitle    = {Advances in Cryptology --- CRYPTO~'99},
pages        = 47--64,
series       = {Lecture Notes in Computer Science},
volume       = 1666,
year         = 1999,
month        = 8,
publisher    = {Springer-Verlag},
}