Tightly security code based two tier signature using chameleon hash functions

Abstract The advancement of quantum algorithms threatens traditional digital signatures, prompting the exploration of post-quantum solutions such as code-based signatures with chameleon hash functions. This study investigates the security effectiveness of chameleon hash-based signatures within the hash-and-sign framework, emphasizing their superior resistance to quantum-based attacks. These signatures provide not only non-repudiation and authentication but also possess non-transferable properties, ensuring their validity is confined to a designated verifier without requiring the private key from the public key holder. Furthermore, the non-interactive nature of the proposed scheme preserves efficiency comparable to that of classical schemes, making it a compelling option for quantum-resistant digital signatures. In this paper, we introduce an innovative Kabatianskii-Krouk-Smeets (KKS) scheme over the finite field $\mathbb{F}_{q^m}$, which represents a significant advancement in cryptographic security. A key component of this proposal is the utilization of Chameleon hash functions, which form the foundation of the KKS scheme and operate using both Hamming and rank metrics. These functions are instrumental in constructing digital signature schemes that deliver not only enhanced security but also improved performance, positioning this framework as a strong contender in post-quantum cryptography. To validate the proposed schemes, we carry out a thorough formal analysis of their security properties, confirming their robustness against key compromise and forgery attacks. Additionally, we perform an extensive performance evaluation to illustrate the schemes' efficiency and practical usability in real-world cryptographic applications. We introduce a two-tier signature scheme combining Chameleon hash functions with KKS schemes. This approach uses rank metrics and large finite fields, enhancing security while maintaining system efficiency through the additional protective layers provided by Chameleon hash functions. MSC: 94A60