<Abstrcat>Based on the information hiding algorithm of color static digital image, the strategy and the algorithm for effectively solving security problems of electronic stamps were discussed.

Electronic Stamp is a necessary technology in developing Electronic Document System.

E-note authentication technology using E-seal watermarking;

This paper designed an order protocol based on E-seal, and using E-seal in order form of E-commerce which ensure the security and reliability in E-commerce.

Design and Realization of Electronic Seal Middleware Oriented E-Government;

Research and Implementation of Electronic Seal System Based on Digital Signature and Quadratic Residue;

It is essential that enterprises have electronic seal to enforce their power and assure the safety of their information systems.

The Electric Seal System Design and Implement Based on Digital Signature;

By using USBKEY,security controls and electric seal technology,it provide effective authentication,access control,authorization, confidentiality,integrality and undeniable ability.

This thesis makes deep research on the all kinds of the techniques about electronic signature firstly.

Traditional written documents, autographs and signature, which used to be commonly used for confirming rights and responsibilities as well as transactions, have been gradually replaced by electronic documents and electronic signature.

Meanwhile, the public faith to ED and the legal validity of it become a problem need to solve immediately, and electronic signature is the solution to the problem.