Study And Analysis Of Proxy Signature Scheme

In modern society, with rapidly development and application of network, people pay more attention to the information security problem. As the technology for ensuring information security, digital signature plays an important role in protecting integrality, unforgeability, undeniability and verifiability of information. Proxy signature, which are a kinds of particular digital signatures, because of its peculiar threshold proxy characteristic, has become one of the major subjects in the cryptography field. This thesis proposes a secure and efficient proxy signature scheme based on RSAOur contribution:First the thesis introduce conception, requirement and categories of proxy signature, and give some typical proxy signature schemes.In 1996, Mambo, Usuda and Okamoto firstly introduced the concept of proxy signature, which allows a designated person, caleda proxy signer, to sign on behalf of an original signer. Mambo et al showed proxy signature should have properties of undeniability, verifiability, unforgeability, distinguishability and identifiablity and so on, and proposed three types of delegation: full delegation, partial delegation and delegation with warrant.We survey the achievements in the field of proxy signature; briefly give a description of various types of proxy signature schemes such as MUO96, Kim etc. signature schemes and threshold proxy signature scheme base on RSA cryptosystems.Then, analysis a few typical proxy signature schemeswe analysis a few typical proxy signature schemes, which have important significance for the development of this study field, show attack scenarios against these schemes. Almost all previous proxy signature schemes are insecure against original signer's forgery.Last, grounded on analyzed basic knowledge of proxy signature, the thesis generalizes the security problems in existing schemes. According to the characteristics of proxy signature schemes, a proxy signature scheme based an RSA is proposed. The thesis analyzes some commconly used attacks detailedly to verify its security,。some problems in the study of this field are presented, and several main research directions are pointed put as well.