With the wide application of camera equipment, digital image, as an important information carrier, has gradually integrated into me their lives. With the popularity of image editing software, people have to re-examine seeing is believing ideas. In recent years, there have been frequent incidents of image fraud in the fields of news media, judicial notarization and scientific research. Therefore, judging the authenticity and originality of digital images has become an urgent problem to be solved in the field of forensics. Tamper often change the image and its information through different image operations which affecting the reader's authenticity of things. Therefore, it is of great significance to detect the operation history of digital images. Based on the above research background, this paper first summarizes the research status of image operation forensics algorithm, and then obtains evidence from digital image muti-operation. The accuracy, practicability and robustness of the algorithm are proposed. In this paper, an image muti-operation forensics method with JPEG robustness is proposed. Experiments show that this method has a good performance in JPEG robust detection with high quality factor and low quality factor.

DESIGNIN AND OPERATION OF DIGITAL EVIDENCE MANAGEMENT SYSTEM APPLYING COMPUTER FORENSICS AND ELECTRONIC CERTIFICATION Digital evidence will be used as a term, which means the electronic form of information which is necessary to confirm or prove the factum of all kinds of behaviors committed through the devices which have data processing ability including computer. It is expected that there will be the increase of legal conflicts surrounding electronic commerce activities as well as the increase of cyber crimes, as the number of Internet users are getting bigger. In order to solve the problems of conflicts derived from electronic commerce, the factum of electronic commerce activities must be confirmed. In order to confirm the factum of electronic commerce activities, the evidence is prerequisite. Almost all evidences relating to the electronic commerce activities exist in digital form. For the reason that the digital evidence can be easily damaged and changed, special management is required to collect, analyze, and preserve the digital evidence. In order to meet this requirement, this study proposes a basic model of digital evidence management system applying computer forensics and electronic authentication.