Efficient Fully-Leakage Resilient One-More Signature Schemes
In a recent paper Faonio, Nielsen and Venturi (ICALP 2015) gave new constructions of leakage-resilient signature schemes. The signature schemes proposed remain unforgeable against an adversary leaking arbitrary information on the entire state of the signer, including the random coins of the signing algorithm. The main feature of their signature schemes is that they offer a graceful degradation of security in situations where standard existential unforgeability is impossible. The notion, put forward by Nielsen, Venturi, and Zottarel (PKC 2014), defines a slack parameter \(\gamma \) which, roughly speaking, describes how gracefully the security degrades. Unfortunately, the standard-model signature scheme of Faonio, Nielsen and Venturi has a slack parameter that depends on the number of signatures queried by the adversary.