APPLICATION OF SECRET SHARING TECHNIQUES ON CONFIDENTIAL FORENSIC INVESTIGATION

How to capture digital evidence is crucial for counteracting against the computer and cyber crimes. However, in a large sharing system (e.g. in a data center or even in a cloud system), cloning the whole set of data for investigation is not feasible and also may have conflict with privacy issues as most of the data is not relevant to the crime. The problem is how to retrieve the relevant information without the investigator knowing other irrelevant data while the server administrator does not know what the investigator is searching. To solve this problem, Hou et al. tried to model the problem as a secure keyword searching problem and proposed a few encryption-based schemes. While the schemes are theoretically sound, the efficiency is a concern. In this paper, we solve the same problem using secret sharing schemes and show that the efficiency can be greatly improved, thus making it practical. We demonstrate the advantages of our solution in terms of computational complexity analysis and experiments. The experimental results show that our solution is much faster in searching and processing the relevant data, so is superior to the existing work.