Research On Forward Security And Strong Blindness

With the rapid development of computer-network and communication technology,there has been big change in information security required by modern society.As well-known,the requirement for information security can be realized mostly by cryptography,in which digital signature is especially important. Digital-signature is an important computer-network security technology,which assures the integrity and authentication of transmitted message.But following the increasing dependence on informatization,the problem of information security becomes marked.It requires increasingly high security property and character possessed by digital-signature scheme.Nowadays,forward-security and strong-blindness have become the central issue of the cryptography study and both of them are also the important aspects of digital-signature.This paper studied the two characteristics.At the beginning of digital-signature scheme design,there are some factors, which cause serious threat to code protocol,should be considered,e.g.scheme security performance,fault of operating system,human error,key disclosure created by internal opponent's attack.The forward-security-signature considers decreasing the influence and loss on system security during the key's disclosing process.The forward-security-character is one of the measure for information-security risk-control. The strong-blind signature-scheme plays the major role in protecting message sender's privacy.If a scheme has strong-blindness,it would have unconditional anonymity.The strong-blind signature-scheme is the best one so far,which has been used in electronic cash system and electronic voting system in e-commerce.Because the forward-security-character and the strong-blindness have different features,sound effect can be achieved by introducing the forward-security-character into the strong-blind signature-scheme.This is their comprehensive usage that can promote e-commerce.The author's main research results are to be as follows. 1.After analyzing,summarizing and comparing the existing signature-scheme with forward-security-character,a forward-security signature-scheme was obtained and the master key mechanism was introduced into the scheme.2.Through introducing the one-way hash chain,the strong forward-security signature-scheme was obtained,which was called two-way secure signature-scheme. The above two signature-scheme,which have forward-security-character,is based on famous signature-system.3.A strong-blind signature-scheme was given and it was based on ElGamal blind signature-system.4.Blind analysis was given to the existing RSA blind signature-system and a strong signature-scheme was constructed.5.Based on the failure-termination signature-system,a strong-blind signature-scheme was designed.6.In view of senior's research,the author introduced forward-security-character into strong-blind signature-scheme and obtained a signature-scheme which had forward-security-character and strong-blindness.