Research On Several Critical Techniques Of Integrity Of Digital Evidence

With the accelerated development of social informatization level and the popularity of applications of the e-government, e-business, etc, thus some social problems and digital information relate in together, the key to settle disputes is to appropriately ensure the digital evidence. As an interdiscipline of law and computer science, the application of digital evidence still lacks further study. Researchers of law investigate the relevant law features and identification of digital evidence, which lack technological features and acquisition methods of digital evidences. The majority of judges stand away from the information technology, there are no rigid constraints to follow, only based on personal experiences, to evaluate the probative force of digital evidence for the judges. But for a particular case to be testified, how much weight does the digital evidence? To what degree does the digital evidence has probative force? It becomes the court debates and a ticklish question for the judges as the judicial evidence.The ease with which digital evidence can be altered, destroyed, or manufactured in a convincing way is alarming, which constrains the widespread utilization of digital evidence in crucial litigious procedures. Protecting the integrity of digital evidence becomes paramount concern for courts, investigation organs and those accused. When studying the digital evidence integrity, some law learners consider it as an important attribute index of the probative value of digital evidence. Protecting the integrity of digital evidence is a complicated technological process, which involves in several aspects such as:fixation of digital evidence source, extraction of digital evidence, analysis and expression of digital evidence. This is also the reason that less research on integrity of digital evidence by the domestic and international academic circles.In this paper, after summarizing the newest academic achievement of computer forensic and the application development requirement of digital evidence, the research subject of digital evidence integrity are briefly introduced. Then the author proposes Chain of Custody as core and law investigation of computer forensic being divided into several module-levels to analyze the integrity of digital evidence. Based on combining the research development of current digital evidence theory, the practical use of the digital forensics and digital evidence application of current court prosecution, this article studies the several critical problems of digital evidence integrity and points proposition solutions, which include:integrity index system of digital evidence and quantitative methods of degree evaluation, Digital timestamp of digital evidence, Digital signature of digital evidence integrity, Integrity assurance of evidence analysis. Some research achievements, such as method of the dynamic labels of the Biba model in forensic evidence analysis, etc. are being applied in reality of computer forensics.