Notes on Theoretical Limitations and Practical Vulnerabilities of Internet Surveillance Capture

Surveillance of Internet communications is increasingly common. As a greater and greater percentage of communication occurs over the Internet, the desire by law enforcement, intelligence agencies, criminals, and others to access these communications grows. In recent years, motivated by updated legislation, we have seen the first large-scale systems for intercepting Internet communications deployed, and there is increasing pressure for more such systems to be developed and put to use. Such systems raise a number of obvious questions for the security research community. Unfortunately, nearly all the systems that have been developed are closed and proprietary, and their inner workings closely guarded for commercial and “security” reasons. Very little research exists in the open academic literature exploring the technical aspects of Internet surveillance, and (to our knowledge) none which focuses on security or reliability. In this work we examine one specific problem, that of performing reliable capture of Internet communications. This work has three main contributions which address some, but by no means all, of the open questions relating to reliable capture in Internet surveillance. First, we provide a survey of the current state of practice for Internet capture in the public literature. Second, we examine a number of ways in which existing capture solutions fall short of perfect capture, and the consequences, namely theoretical vulnerabilities as well as practical attacks on the accuracy and completeness of information analyzed. Finally, we construct a set of improved capture tools which provide stronger, more reliable results when used in conjunction with existing tools. This document represents a dissertation in progress.