Key Evolving Attribute‐Based Signature Under Short Integer Solution Problem

Key exposure is a severe threat in digital signature, the scheme will be compromised provided that the private key of the signature is revealed. To remove the destruction of key exposure, the private key must be kept updated in the process of the signature. As a new cryptographic primitive, Attribute‐based signature (ABS) scheme has the limitation in practical applications because the private key may be leaked. So far, very little works have focused on the key leakage of ABS, especially in the setting of lattices. To deal with the problem, we present the construction of Key evolving attribute‐based signature (ke‐ABS) under Short integer solution (SIS) problem. As a new research field in the point, our scheme has considered a threshold access structure, which allows users with attributes satisfying the defined policy that can generate a valid signature without revealing more information. Compared with the known schemes, our scheme provides an assurance of unforgeability and attribute signer privacy.