Research And Implementation Of Secure Proxy Signature System

In the real world .people often delegate some of their rights,such as signing right,to reliable proxy and let proxy perform these rights on behalf of them.In 1996,the concept of proxy signature is firstly set forth by Mambo,according to authorization,proxy signature is classified into three categories: full delegation, partial delegation and delegation by warrant.The partial delegation is classified into two kinds: proxy-protected and proxy-unprotected.At the same time,he gives a scheme on partial delegation.It provides foundation for proxy signature.Main works in this dissertation are as follows:(l)In order to ensure disclosing key for signature but signature not be forged,idea of forward-security is introduced into proxy signature,proxy signature based on forward-security is formed.At the same time , time tag is put into this scheme.Because time tag in proxy signature is verified every time ,the scheme can resist attack of replay.(2) In the designed system, except proxy signatory, key for proxy signature is not produced by others on behalf of proxy signatory, it basically satisify not strongly being forged.At the same time, because of accredit, and proxy signatory abusing proxy authority is prevented.(3) According to the principle of proxy signature and basing on two above mentioned, model of proxy signature is designed and basic function is simulated.