Research On ID-based Ring Signature In The Standard Model

With the rapid development of the computer and Internet, the technology of computerand network had brought more and more conveniences and benefits to the people. At the sametime, the corresponding information security problems became more and more serious. Thedigital signature was considered as a primary authentication means of the information security,it has played an important role in solving the problem of information security. The digitalsignature is similar to the simulation of handwritten signature of traditional; it has mainlyapplied in the identity recognition, data integrity, non repudiation and so on. In order to meetdifferent needs, some new signature types had been proposed, such as the threshold signature,blind signature, proxy signature, identity based signature, group signature, ring signature andso on. The digital signature has been a very important part and a hot research topic ofcryptography.Ring signature is a special digital signature technology; it was considered a securecryptography technology to leak a secret. In the ring signature, there does not need the ringadministrator, anyone can spontaneously form a ring containing himself. The ring memberscan use his private key and the public keys of all the ring members to generate a ringsignature for the message. The actual signer’s identity is unconditionally anonymous. Becauseof the unconditional anonymity, ring signature has a special status in the privacy protection, ithas been widely applied in the system of the e-government, e-voting, e-auction, and vehiclesnetwork.The ring signature model has two main types: the random oracle model and the standardmodel. The random oracle model is considered as a kind of heuristic proof, it requires thehash functions are the real random hash function, however, the has functions are pseudorandom in the implemented environment. Even if been proved to be secure in the randomoracle model, the ring signature may not be secure in practice. The standard model has solvedthis problem reasonably. The ring signature in the standard model has been proved secure intheory; it is also secure in the practical application. However, compared with the randomoracle model, ring signature of the standard model is inefficient in computational efficiencyand reduction efficiency.In this paper, our study focuses on the ring signature in the standard model, and weobtained the following research results:1. The security of some ring signature schemes in standard model were analyzed in thispaper. We found that these schemes can not satisfy the unforgeability of ring signatures, andthe corresponding forge attack methods were illustrated in this paper; 2. We found a new attack method of ring signature in the standard model. That is that alegitimate ring member can generate a valid ring signature, however, the ring did not containthe actual signer. There exists the hidden trouble that one legitimate member may frame theother ring members;3. A proved secure ID-based ring signature scheme in the standard model was proposed,and its corresponding security proof also been given in this paper. The proposed scheme is notonly satisfy the unforgeability of the general ring signatures, but also it can resist the groupchange forge attack, the multiple-know-signature existential forge attack.