The Theory Of Blindness And Anonymity In Digital Signatures And Its Application Research

Digital signature is the key component of cryptographic technology.It has the properties of authentication,integrity and non-repudiation and therefore is widely used in e-commerce and e-government.Blindness and anonymity are two important properties provided by some special signatures.Blindness can ensure that the content of signing messages is unknown to the signer.Anonymity can guarantee the identity of a group member who signs messages on behalf of the group is unknown to outsiders.They are widely used in the protection of individual privacy.This paper discusses the construction of blind signature scheme which has the property of blindness and group signature scheme which provides anonymity.Of course,we can obtain a group blind signature scheme,which has the properties of blindness and anonymity,by combining the above two schemes.Combining multi-signature and threshold signature,we find a simple and new way to the construction of group signature schemes.Using this method,based on the famous BLS short signature scheme,we get an efficient short group signature scheme.It has the advantage of simple structure and short signature length.Furthermore,It has easily solved the instant join and deletion of group members.Combining this signature scheme with a blind signature scheme based on the BLS short signature,a highly efficient group blind signature scheme is obtained.We also discussed the practical application of blindness and anonymity.Using blind signature scheme,an electronic cash system and an electronic voting system are constructed respectively.It can only support single bank and single management agency.A group blind signature can build an electronic cash system that supports multiple banks and an electronic voting system that supports multiple management agencies.