Design And Implement Of Digital Signature Client Based On PKI

With the information of the society expanding, the integrality and unalterable of the electronic file and the signer verifying attract significant coverage from people.This thesis makes deep research on the all kinds of the techniques about electronic signature firstly. Aiming at the electronic signature using the PKI technique, the thesis analyses the theory and the technique about it. It realizes several functions as follows: (1) Existing with groupware pattern, the electronic signature inserts into the Word, Excel and so on document. (2) Document signature function: make sure visible sign the present document, it can sign all the places in the document. (3) Signature authenticate function: authenticate the signer's factuality and reliability. (4) Document authenticate function: everyone can authenticate the integrality of the document. (5) Cancel signature: users can cancel the signature using this function when users are not satisfy with it or some reasons. (6) Check up the certificate: check up the signer's information. (7) Signature has cosigned function.Then it designs the electronic signature existing with the COM groupware using the PKI technique. When designing the electronic signature, it makes full advantage of the CryptoAPI function and the CAPICOM groupware. The electronic signature of the PKI technique uses the RSA public key cryptography and the hash function to carry out the authentication function. At last, it proves the system's security in theory.This system possesses of advantages such as simple using, cheap cost and high security, and has wind foreground.