Date Added: Dec 2009
Authentication and secrecy are two crucial concepts in cryptography and information security. Although independent in their nature, various scenarios require that both aspects hold simultaneously. For information-theoretic or unconditional security (i.e. robustness against an attacker that has unlimited computational resources), authentication and secrecy codes have been investigated for quite some time. The initial construction of authentication codes goes back to Gilbert, MacWilliams & Sloane. A more general and systematic theory of authentication was developed by Simmons. Fundamental work on secrecy codes started with Shannon.