@inproceedings{2342f86d17b344c78dd8dbd4b959f69d,

title = "Stronger security bounds for Wegman-Carter-Shoup authenticators",

abstract = "Shoup proved that various message-authentication codes of the form (n,m) ¿ h(m) + f(n) are secure against all attacks that see at most $\sqrt{1/\epsilon}$1 authenticated messages. Here m is a message; n is a nonce chosen from a public group G; f is a secret uniform random permutation of G; h is a secret random function; and e is a differential probability associated with h. Shoup{\textquoteright}s result implies that if AES is secure then various state-of-the-art message-authentication codes of the form (n,m) ¿h(m)¿+¿AES k (n) are secure up to {\"O}{ 1/e}1 authenticated messages. Unfortunately, {\"O}{ 1/e}1 is only about 250 for some state-of-the-art systems, so Shoup{\textquoteright}s result provides no guarantees for long-term keys. This paper proves that security of the same systems is retained up to {\"O}{#G}#G authenticated messages. In a typical state-of-the-art system, {\"O}{#G}#G is 264. The heart of the paper is a very general {"}one-sided{"} security theorem: (n,m) ¿ h(m) + f(n) is secure if there are small upper bounds on differential probabilities for h and on interpolation probabilities for f.",

author = "D.J. Bernstein",

year = "2005",

doi = "10.1007/11426639_10",

language = "English",

isbn = "3-540-25910-4",

series = "Lecture Notes in Computer Science",

publisher = "Springer",

pages = "164--180",

editor = "R. Cramer",

booktitle = "Advances in Cryptology - Eurocrypt 2005 (24th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Aarhus, Denmark, May 22-26, 2005, Proceedings)",

address = "Germany",

}