Research On Authentication Watermark Technique And Its Application In Electronic Signature System

Along with the continuously development of the computer network and the information science, the integrity and the security of the digital media receives more and more attention. The authentication watermark is widely applied in the digital media complete protection. Watermark information which has the special function was hided into media information through the insert algorithm. It becomes a research hot spot which used in the digital media information authentication.First,this article introduces the authentication watermark classification,the algorithm performance appraisal target,then analyzes the authentication watermark typical algorithm,and summarizes its excellence and disadvantage. The article proposes the authentication watermark model. On analysising the statistical property foundation of signature image,it proposes a authentication watermark algorithm based on the JPEG signature image. It picks-up the image frequency range characteristic withdraws the humanity visual characteristic. It uses the fuzzy threshold method to determine the watermark inserts the region. Through the the examination and authentication of tested image,it differentiates the normal imagery processing and the malicious attack and locate the tampers region. This article proposes a text authentication watermark algorithm based on the character characteristic. The algorithm withdraws the abstract value of text character coding value as the characteristic value,and realizes the watermark information inserting according to periodic sine wave rule throught adjustmenting the character gary-scale value. All of these conform to the human visual system performance.Finally,this article applys the authenticate watermark in the electronic government affairs. It rests on the characteristic of the administration system of our army.Combining the authentication watermark technology and the multi-signatures echnology et al.,the authentic protection electronic signature system was designed and carried out, which used to protect the text integrity. This system uses the COM compilation, which is advantage for second development.