Tightly Secure Chameleon Hash Functions in the Multi-User Setting and Their Applications

ePrint Report: Tightly Secure Chameleon Hash Functions in the Multi-User Setting and Their Applications

Xiangyu Liu, Shengli Liu, Dawu Gu

We define the security notion of (strong) collision resistance for chameleon hash functions in the multi-user setting ((S-)MU-CR security). We also present three constructions, CHF_dl, CHF_rsa and CHF_fac, and prove their tight S-MU-CR security based on the discrete logarithm, RSA and factoring assumptions, respectively. In applications, our tightly S-MU-CR secure chameleon hash functions help us to lift a signature scheme …

applications eprint report functions hash