Paper 2019/1232 Original: eprint.iacr.org/2019/1232 ↗

Efficient Construction of Nominative Signature Secure under Symmetric Key Primitives and Standard Assumptions on Lattice

Abstract

Nominative signature is a cryptographic primitive where two parties collude to produce a signature. It is a user certification system and has applications in variety of sectors where nominee cannot trust heavily on the nominator to validate nominee’s certificate and only targeted entities are allowed to verify signature on sensitive data. We provide a new construction for nominative signature from standard assumptions on lattice. Our construction relies on collision resistant preimage sampleable function and symmetric key primitives like collision resistant pseudorandom function and zero knowledge proof system ZKB++ for Boolean circuits. We provide a detailed security analysis and show that our construction achieves security under unforgeability, invisibility, impersonation and non-repudiation in existing model. Furthermore, our construction exhibits non-transferability. The security under non-repudiation is achieved in the quantum random oracle model using Unruh transform to ZKB++.