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Research On Theory Of Digital Signature With Special Properties

Posted on:2010-07-13Degree:DoctorType:Dissertation
Country:ChinaCandidate:X S XiaFull Text:PDF
GTID:1118360275986726Subject:Information security
Abstract/Summary:PDF Full Text Request
With the rapid development of computer network and e-commerce, the security problems of data transmission and identification and authentication of both sides involving a business are becoming more and more exigent. The common digital signature scheme can't meet with the requirements of many new applications to be used widely, since they require that digital signature scheme can support some special purposes and functions such as forward-secure signature applied in risk control,proxy-signature applied in electronic payments, threshold group-signature applied in issuing important military orders, multi-signature applied in reviewing and approving official document step-by-step, ring-signature applied in making a report anonymously, and so on. Therefore, the research on special application-oriented digital signature scheme is becoming an important research direction of digital signature area.The elliptic curve cryptosystem(ECC for short), which has low bandwidth, shorter key length and signature length and similar level of security to other cryptosystem, is very appealing in wireless network.An efficient dynamic threshold-signature scheme based on ECC is proposed, which has not only the characteristics of dynamic threshold-signature but also meets with the requirements of untraceability and anonymity of group-signature, as well as can resist conspired attack. Furthermore, few system parameters are required to be changed as a group manager joins or a group member is removed.By analyzing several present forward secure proxy signature schemes based on discrete logarithm cryptosystem, the paper finds that one of these schemes updates the proxy signature secret key in its algorithm of secret key updating and the proxy signature expression includes the proxy signer's private key,necessary factor's exponential function of some of these schemes don't include crucial parameter,these schemes don't meet all necessary condition of forward security gived by the paper, so these schemes haven't the charactistics of forward security. One of them can't resist forgery attack from anyone as the private key of proxy signers are lost. Some of them haven't also the basic characteristics of proxy-signature because them can't resist forgery attack from anyone or original signer even if attackers haven't known any secret information about the signatures. To solve above secure defects, the paper propose a new modified and high efficient proxy-signature scheme that updates the proxy private key in its algorithm of secret key updating, necessary factor's exponential function of the scheme includes crucial parameter,Analysis results show the scheme has not only the characteristics of forward security but also all security characteristics of strong proxy signature. Because bilinear pairings has high efficience and security in implement.Realising most of present forward secure proxy signature schemes based on discrete logarithm have low implement speed and system security.A new forward security proxy signature scheme based on bilinear pairs is proposed, the key update algorithm of the scheme was designed based on several cryptology difficult problem,it will change current sitution that it is very difficult to design a forward security proxy signature scheme based on bilinear pairs and the key update algorithm of most of present forward secure signature schemes was designed based on one cryptology difficult problem such as Modulo Composite quadratic Residuosity. Therefore, the scheme is efficient and secure.By introducing the concept of forward security, a new multi-signature scheme with proxy is firstly proposed. The scheme can not only improve largely the efficiency of signature and validation through pre-calculation, but also has the characteristics of high security, high efficiency and high availability. Also, a forward security multi-signature scheme is analyzed. It can't resist forgery attacks as the secret keys of signers are revealed, and hasn't the charactistics of forward security. Based on the scheme, an improved forward security multi-signature scheme is proposed, which can reduce the procedures of multi-signature and increase signature efficiency.Based on the bilinear pairs technique, a secure certificateless structured multi-signature scheme and a secure certificateless structured muli-signature scheme with signers' intentions are proposed. The singers' secret keys in these two schemes are generated by members and the secret key distribution center jointly, rather than only by the secret key distribution center. They can avoid the forgery attacks from the secret key distribution center, to enhance security degree greatly. Analysis results show the two schemes can resist any forgery attacks and conspired attacks (including KGC).Two secure schemes of certificateless ring-signature and certificateless ring proxy signature based on CL-PKC are proposed. Same as above two muli-signature schemes, the secret keys of singers in these two schemes are also generated by members and secret key distribution center cooperatively, so that their security is higher than the common ring-signature schemes based on identity. Analysis results show the two schemes can resist forgery attacks and conspired attacks (including KGC), and can meet with the requirements of unconditional anonymity of signers. In additional, the ring proxy signature scheme has all security characteristics of strong proxy signature.
Keywords/Search Tags:forward security, proxy-signature, multi-signature, bilinear pairs, CL-PKC, threshold group-signature, ring-signature
PDF Full Text Request
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