IACR News item: 21 October 2019
Efficient Construction of Nominative Signature Secure under Symmetric Key Primitives and Standard Assumptions on Lattice
Meenakshi Kansal, Ratna Dutta, Sourav MukhopadhyayePrint Report
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 nominees 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 of ZKB++.
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