Proposal of Digital Forensic System Using Security Device and Hysteresis Signature

With the development of the Internet society, digital forensics, i.e., the technology and procedures used to prepare digital evidence for litigating against Internet crime, has been used extensively. In particular, digital forensics used in the corporate world, primarily in relation to litigation involving computer-related evidence in civil matters such as breaches of contract or breaches of confidence, has recently gained a great deal of attention. Digital forensics requires the following two functions: (1) All records must be left unaltered if they are handled in a computer, and (2) the record must be tamper-resistant. In order to realize these functions in a standalone environment, we developed a system named "dig-force" (digital forensic system with chaining signature for evidence) that uses a USB device with a smart card function and a hysteresis signature based on digital signature technology. In this paper, we report the proposed system and the evaluation results of the function and performance of the system with this prototype program.