Short Undeniable Signatures Without Random Oracles: the Missing Link

Fabien Laguillaumie (1) , Damien Vergnaud (2)

1 TANC - Algorithmic number theory for cryptology
2 LMNO - Laboratoire de Mathématiques Nicolas Oresme

We introduce a new undeniable signature scheme which is existentially unforgeable and invisible under chosen message attacks without using any random oracle. The scheme is a simple embedding of Boneh and Boyen's recent short signature scheme in a group where the decisional Diffie-Hellman problem is assumed to be difficult. The invisibility of our scheme relies on a decisional variant of the strong Diffie-Hellman assumption, while its unforgeability relies on the strong Diffie-Hellman assumption.

Domaines: Cryptographie et sécurité [cs.CR]

Fabien Laguillaumie, Damien Vergnaud. Short Undeniable Signatures Without Random Oracles: the Missing Link. Indocrypt 2005, Dec 2005, Bangalore, India. ⟨inria-00001122⟩