A provably secure code‐based concurrent signature scheme

Abstract

Concurrent signatures allow two entities to generate two signatures in such a way that both signatures are ambiguous till some information is revealed by one of the parties. This kind of signature is useful in auction protocols and in a wide range of scenarios in which involving participants are mutually distrustful. In this study, to have quantum-attack-resistant concurrent signatures as recommended by National Institute of Standards and Technology (NISTIR 8105), the first concurrent signature scheme based on coding theory is proposed. Then, its security is proved under Goppa Parameterized Bounded Decoding and the Goppa Code Distinguishing assumptions in the random oracle model. In addition, performance evaluation shows that the proposal is approximately as efficient as Dallot scheme. The authors should highlight that their proposal can be a post-quantum candidate for fair exchange of signatures without a trusted third party in an efficient way (without a high degree of interactions).