Resrarch On Multisignatures And Multisigncryptions From Identity-based

Digital signature, which can prove authentication, integrity and non-repudiation, is one of the key techniques of information security and plays a very important role in E-commerce and E-governance. As the deepening of digital signature research and the rapid development of internet, the standard signature, which is a simple simulacrum of handwritten signature, and can't still meet the need in practice, thus making research on the digital signatures with additional properties becomes a main research direction in digital signature. But a mass of the existing signatures with additional properties are sigle-signatures, and a few existing multi-signatures with additional properties is in public key infrastructure (PKI) system, and they have managing public-key certification problems of complexity and high cost. So, we research the multi-signatures and multi- signcryptions algorithm.The conclusion in this paper is as follows:1. We present an identity-based multi-signature scheme. Key feature of the proposed scheme is that, the length of the scheme has nothing to do with the number of signatories, and some calculations can be performed beforehand. In addition the security of the scheme is discussed. By security analysis, the proposed signature scheme can effectively resist many kinds of attacks such as replay attack.2. We present an identity-based Blind multi-signature from bilinear pairings for offsetting the existing blind multi-signatures scheme. We analyze correctness, undeniability and unforgeability of the proposed Scheme. The scheme have both of the blind signature's anonymity and the multi-signature'characteristics, and it could have better practical applications in electronic cash or electronic election.3. We present an identity-based blind multi-signcryption scheme from bilinear pairings. The scheme could decrease the cost of building and managing public key infrastructures; the expense of the users'management of public-key and their certificates is avoided. We have a safety and efficiency of analysis,that the proposed scheme is proved to be secure assuming the Bilinear Discrete Logarithm Problem is hard. 4. We present an identity-based threshold blind multi-signature from bilinear pairings on the elliptic curve by adopting threshold cryptography and blind signature scheme. It analyzes the security and efficiency of this scheme. This scheme has several security characteristics, such as blindness, non-forgery etc.