The Improvement Of A Ring Signature Scheme Based On Lattice

With the progress of network information technology,the cryptosystem based on the mathematic difficult problems such as the large integer factorization,discrete logarith-m,double linear,whose security face serious challenges,they cannot resist quantum at-tack.Once appear a quantum computer,these cryptographic protocols will be completely break in polynomial time.The cryptosystem based on the lattice difficult problem is a new type of public key cryptosystem.It can resist quantum attack,so far,there is no quantum algorithm can solve the difficult problems in lattice in polynomial time.Wang and Sun put forward a ring signature scheme based on hard problem in the lat-tices,but it is not satisfied unforgeability against insider corruption.Basing on their result-s,we present a modified ring signature scheme by adding the set of ring member public key into hash function,that can guarantee it's security.Then we prove the security of our scheme which is anonymous against full key exposure and unforgeable against insider corruption in the random oracle model.On the other hand,our scheme is based on the one-way trapdoor function,the efficiency of the trapdoor generation algorithm determine the efficiency of the signature scheme.We use strong trapdoor generation algorithms putting forward by Mic-ciancio which is simple and efficient.Thus our scheme is more simpler,efficient,easier to implement than the original.