A new approach to secure logging

Abstract

The need for secure logging is well-understood by the security professionals, including both researchers and practitioners. The ability to efficiently verify all (or some) log entries is important to any application employing secure logging techniques. In this article, 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 to secure logging 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 online trusted third parties or secure hardware. We also investigate the concept of immutability in the context of forward-secure sequential aggregate authentication to provide finer grained verification. Finally we evaluate proposed schemes and report on our experience with implementing them within a secure logging system.