An Electronic Auction Protocol Based On Partially Blind Signature And Ring Signature Theory

Blind Signature theory has been used in numerous applications since it was brought forward in 1982, because of its protection for the secrets. It is used to keep the users' identities in e-commerce, such as anonymous e-voting and anonymous e-cash. To be simple, blind signature allows a user to obtain one signature on the user's secret, which is out of the view of the signer. In 1996, Abe and Fujsaki proposed the conception of partially blind signature for the first time. There are some common information shared between the user and the signer, which is the only difference between the partially blind signature theory and blind signature theory.Ring signature theory was first proposed by Rivest and Shamir in 2001. They gave two ring signature protocols, based on RSA and Rabin, respectively. The security under Random Oracle model of the former one was also proposed in their paper. Actually, ring signature is just a simplified group signature, which allows any member of the group to sign the information efficiently without anybody's corporations, while his exact identity is perfectly protected. There are some difference between ring signature and group signature. No group organizers exist in ring signature, and no revoke process and no corporations are needed between the signer and the other members. Every member could sign a piece of information legally without the help or intervenes of anyone, as long as he has the public keys of all the members and his own secret key which is kept secure from other people. Because the people out of this group do not have such a secret key, he could not generate a legal signature of the information. When the verifier receives such a ring signature, what he could do is to verify whether this signature is signed by the member of the group and whether it is a legal ring signature, but nothing about the identity of the actual signer.We proposed an electronic auction protocol, based on partially blind signature theory and ring signature theory, which satisfies the following requires on security: the anonymity of the bidders, the validity of the winners' identities, the anonymity of all bids, the undeniability of the seller and so on. After the protocol, we gave the proofs of the security under the standard model instead of Random Oracle model.