Multiplicative forward-secure threshold signature scheme

Abstract

The devastating consequence of secret key exposure in digital signature is that any signature can be forged and cannot be trusted. To mitigate the damage of secret key exposure, forward-secure signature schemes and threshold signature schemes are devised. In this paper, we propose a robust forward-secure threshold signature scheme with the applicability to mobile ad-hoc network in mind. Our main objective is to reduce interaction among the set of signers and to reduce the dependency on broadcast as well as private point-to-point connections. We achieve this by avoiding the regular polynomial sharing and employing multiplicative sharing in a threshold structure. The security of our proposed threshold scheme is reducible to the security of a single-user scheme, which has been proven secure under the random oracle model.