Research On Identity-Based Group Signature Scheme

With the rapid development of information technique and the large-scale application of network technique, information security has been becoming more and more important, and is becoming a generally concerned research topic in domestic and international computer and network application field. As the main means of the authentication, the digital signature has provided an important technique for information security. As an important branch of the digital signature, group signature can achieve some special authentication requirements. In this paper, the identity-based group signature and the confidentiality of message in group signature are discussed. The main works are as follows:The research status and the development trend of the group signature are summarized. The concept, some secure properties and the applied foreground of group signature scheme are also described. At the same time, some variants of group signature are briefly introduced.The characteristics of identity-based cryptosystem and identity-based group signature scheme are analyzed. In general identity-based cryptosystem, the problem of key management can be simplified, but private key generator must be unconditionally trusted, which restricts the use of identity-based cryptosystem.An identity-based designated recipient group signcryption scheme without trusted private key generator was proposed. In the scheme, any member of the group can signcrypt on behalf of the group which is composed of n members. Only the designated recipient can recover the signcrypted plain message from the ciphertext to verify the validity of the group signcryption.The proposed scheme can also be converted into a group signature scheme with public verifiability by publishing the relevant information by the designated recipient, which does not disclose the plain message. Moreover, the confidentiality, authenticity and non-repudiation of message are guaranteed simultaneously. The proposed scheme provides effective solutions to group-oriented authentication and its confidentiality in open network.