Post-quantum secure identity-based signature achieving forward secrecy

Abstract

Identity-based cryptography (IBC) has gained significant attention over the years by enabling authentication of public key of a party without relying on certificates. Since the discovery of IBC, we have witnessed several ID-based identification (IBID) and identity-based signature (IBS) schemes in the literature. However, most of them depend heavily on discrete logarithm problem, making them susceptible to quantum attacks. This necessitates the development of IBID and IBS schemes that are immune to quantum attacks. In this work, we reveal the shortcomings of the recently (Peng et al., 2020) proposed isogeny-based IBS by Peng et al. We have discovered severe vulnerabilities in the key component of their IBS scheme, which rendered their IBS scheme unable to meet their claimed security guarantees. More positively, we have adopted a potential framework to resolve the flaws in their scheme. This led us to develop the first isogeny-basedIBID scheme that provides security against impersonation under passive attacks.The practical deployment of IBS in surveillance systems raises subtle security issues that should be addressed. To resolve these problems, we have also devised the first forward-secure identity-based signature (FSIBS) from isogenies. The comprehensive study of provable security reveals that our scheme provides correctness, forward security and is immune to forging attacks.