Secure checkpointing

Abstract

Fault-tolerant computer systems are increasingly being used in such applications as e-commerce, banking, and stock trading, where privacy and integrity of data are as important as the uninterrupted operation of the service provided. While much attention has been paid to the protection of data explicitly communicated over the Internet, there are also other sources of information leakage that must be. addressed. This paper addresses one such source of information leakage caused by checkpointing, which is a common method used to provide continued operation in the presence of faults. Checkpointing requires the communication of memory state information, which may contain sensitive data, over the network to a reliable backing store. Although the method of encrypting all of this memory state information can protect the data, such a simplistic method is an overkill that can result in a significant slowdown of the target application. A much more efficient method is to use incremental checkpointing (IC), in which only the modified memory data is saved in stable storage. This paper examines ways to combine the operations, required to perform IC with those required to encrypt this memory state data. Our analysis show that the proposed secure checkpointing schemes increase the overhead by 1.57 when compred to conventional checkpointing schemes, which shows the proposed schemes are feasible. (C) 2002 Elsevier Science B.V. All rights reserved.