基于Falcon的盲签名方案OA北大核心CSTPCD

Lattice based cryptosystem is a mainstream research direction in post quantum cryptog-raphy.Therefore,it is of great significance to construct blind signature schemes on lattices.Based on the theory of blind signature and NTRU lattice,and combining the winning algorithm Falcon of the NIST post quantum cryptography standardization project,this paper designs a compact blind signa-ture scheme.During the process of message blinding,the user performs a bitwise XOR operation on a random binary string with a size of 320 bits generated by the signer and a locally uniformly generated random string of equal length to obtain a 320-bit random binary string in a real signature combina-tion,thereby achieving the blindness of this part of the signature.Splicing the original message with the uniformly generated random string described above can get a message with multiple legitimate signatures.Under the"Hash-then-Sign"paradigm,the signer uses the fast Fourier trapdoor sampler to find a closest lattice point to a point on its coset on an NTRU lattice.After that,the blind signature that meets the requirements can be calculated.The user can obtain a legal signature of the message by performing an unblind operation on the blind signature.Based on the hardness assumption of the SIS problem on NTRU lattice,it is proved that the proposed scheme satisfies strong unforgeability in a random oracle model.The efficiency analysis shows that,both the size of the public key and that of signature combination generated by this scheme are small,which can effectively save bandwidth resources.