Research On Multiple Media Supported Digital Forensic Method And Platform

Nowadays the development of information technology has made electronic data exist everywhere, yet it brings rampant crimes which use digital devices as tools or medium. Digital forensic emerged as a response to this kind of crime. However, digital evidence has not been clearly defined by our legislation, which also has been vulnerable, abstract and diverse. That brings new challenge to digital forensic method under multiple media environment.This paper did research on the key problems of digital forensic based on the local legal environment and the analysis of process model and techniques and tools. Then proposed a digital forensic method by solving those problems and implemented a digital forensic platform to verify the feasibility.In this paper, we firstly analyzed the legal definition of digital evidence and digital forensic techniques and tools, based on which we proposed solutions for the two key problems of digital forensic under multiple media environment. The first one was to design a unified format for digital evidence. We solved that problem by improving the Digital Evidence Bag, for it was public and can support different digital evidence source. We improved its support for digital signature and three levels flow, made the digital evidence format more unified and easy-to-use. The other one was to design a method for credibility guarantee of digital forensic. By using digital signature link that contains flow metadata, we made our method met the requirements of integrity, verifiability and ordering, and was able to guarantee the integrity of evidence and the credibility of results during the process of digital forensic.Based on the research above, we proposed the multiple media supported digital forensic method, which supports"evidence search, evidence keep, evidence analyze and evidence display"under multiple media environment. We designed the key activities and the digital evidence storing in detail. Then, based on the method, we completed the requirements analysis and architecture design of a digital forensic platform using UML, and implemented the platform by Java, OpenSSL, hibernate and MySQL database. Finally we did some function experiments on those key activities. The experiments showed that the platform could not only manage the process of digital forensic but also well support evidence from multiple media and guarantee the credibility of digital forensic process.