A New Approach to Secure Logging

The need for secure logging is well-understood by the security researchers and practitioners. The ability to efficiently verify all (or some) log entries is important to any application employing secure logging techniques. In this paper, we begin by examining the state-of-the-art in secure logging and identify some problems inherent to systems based on trusted third-party servers. We then propose a different approach based upon recently developed Forward-Secure Sequential Aggregate (FssAgg) authentication techniques. Our approach offers both space-efficiency and provable security. We illustrate two concrete schemes --- one private-verifiable and one public-verifiable --- that offer practical secure logging without any reliance on on-line trusted third parties or secure hardware. We evaluate proposed schemes and report on our experience with implementing them within a secure logging system.