Privacy enhanced secure compact attribute-based signature from MQ problem for monotone span program

Abstract

The rapid advancement of computer networks has led to an increase in the exposure of messages within an open environment (cloud). Therefore, the confidentiality of the user's signing information is extremely essential to handle unauthorized access and alterations. Attribute-based signature (ABS) scheme is a significant primitive that ensures the privacy of the user's signing information. To endorse a message, the signer can generate a signature with his/her attributes that satisfy a policy without revealing any other information. Post-quantum attribute-based signature schemes are attractive construction options whose safety do not collapse in presence of quantum computers. This article presents the first attribute-based signature scheme in multivariate quadratic (MQ) setting. To generate the secret signing key, the salted-UOV technique is employed in our protocol. While signing, the well-known 3-pass identification protocol is coupled with the Fiat-Shamir transformation. More positively, our candidate relies on presenting the policy as a monotone span program. We also study existential unforgeability and the perfect privacy feature which ensures that a signature cannot be linked to any signing information. Moreover, our scheme is compact in the sense that it performs efficiently in terms of storage when contrasted to the existing post-quantum attribute-based signature schemes.