Cryptanalysis of a quantum identity-based signature and its improvement

Abstract

Digital signatures are one of the key cryptographic components for providing authenticity and non-repudiation. To circumvent the need of certificates, Shamir in 1984 introduced identity-based signature (IBS). Nearly all of the existing state-of-the-art IBS schemes are relying on the number-theoretic hardness assumptions. Unfortunately, these hard problems are insecure and face a threat in quantum world. Thus, it is high time to design and analyze IBS algorithms that can resist quantum attacks and provide long-term security. Quantum cryptography is one such technique to provide quantum-safe IBS. In this paper, we cryptanalyze the quantum cryptography-based IBS of Huang et al. (Huang et al. in Quantum Inf Process 22(1):36, 2022). We show that the design in (Huang et al. in Quantum Inf Process 22(1):36, 2022) is not secure against public key generator forgery attack, collusion attacks, and intercept and resend attacks. Next, we modify the design of (Huang et al. in Quantum Inf Process 22(1):36, 2022) and propose a new quantum IBS (namely qIBS) which is secure against the aforementioned attacks.