The Research Of The Key Arithmetic Of Digital Seal System

With the rapid development of OA (Office Automation), e-document transmits between different networks more and more frequently. E-document provides a shortcut of information transmition, but at the same time, it gives us some challenges:①How to make sure the real identity of the sender.②How to make sure the integrality of the document.③How to avoid the sender refuses to admit that he is the sender of the document which is sent by himself. The purpose of the digital seal is to solve those problems, and it provides a safeguard for the transmission of the documents between different networks.The paper provides a scheme of digital seal system. By dint of the technologies of PKI,digital certificate and the arithmetic of digital signature, the scheme can make sure the identity of the sender. By digital watermarking, it implements the transmission of the digest of the e-document. By signing the seal to the e-document, the user can be sure the integrality of the document and the identity of the sender. The paper gives further research to the key arithmetic of the seal system, including the digital watermarking arithmetic and the digital signature arithmetic, and puts a new arithmetic of binary image watermarking. The arithmetic bases on the digital seal system. By embedding visible watermarking to the seal image, improving the ability of the seal image to hide information, and obtained good result. The scheme adopts ECDSA which is the most security arithmetic of digital signature, and with its excellence in security and speed to optimize the system. In the end, with the analysis of the arithmetic, implemented the arithmetic of digital watermarking and ECDSA.For validating the proposed scheme of seal system, the paper achieves the basic function of the seal system according to the proposed scheme. By the function testing, it validates the proposed scheme is a feasible and validly scheme.