Research On External Time Channel Shielding Algorithm Based Redundant Code Insert

With the rapid development of computer network technology, especially the rise of cloud computing in recent years, how to solve the information leakage on the computer and network, has become a pressing issue. However, the traditional security mechanisms cannot provide an effective guarantee for information end-to-end security, For example, traditional access mechanisms usually only check the authorization mechanism of information access, without any restrictions on the use of information. After the authorized access to confidential information, confidential information may be leaked, still.Most of the work about confidential information flow, are only concerned about direct or indirect information flow checking. However, confidential information can also be leaked via timing channel leakage to external observers(attackers). Timing leakage occurs when the program encodes the secret data in its timing behavior, observers can get the execution time of this code by external measurements. Therefore, in determining a program is information secure or not, checking external timing channel are equally important.To solve this problem, this thesis proposed a method based on redundant code insertion to balance the program execution time. With a simple imperative language as a working example, the corresponding algorithm is proposed. Finally, the implementations of the algorithm are presented. The analysis of the sample program shows that the converted program does not exist the original external timing channel. Achieve the goal of the protection of confidential information.