An Efficient Lattice-Based Proxy Signature Scheme without Trapdoor

Lattice-based proxy signature is a kind of signature that can resist the known quantum attack and a special digital signature which has the proxy functionality. So far, as far as I know, all lattice-based proxy signatures that use the "hash-and-sign" method of GPV08 signature are low efficient due to the time-consuming preimage sampleable algorithm. Based on the rejection sampling technique of Lyu12 signature, we proposed an efficient lattice-based proxy signature scheme without trapdoor, and the formal security proof of existentially unforgeable is given in random oracle model. In addition, the length of keys and signature in our scheme are shorter than all existing lattice-based proxy signature schemes, and the computations are also small.