| Advancements in computing, though invaluable to the success of the field, have had side-effects: for computers to become both more powerful and easier to operate for the lay user, the complexity of underlying systems has had to increase immensely. Seemingly straightforward operations entail layers of code to execute, of which the user has little awareness. As a result, guaranteeing privacy or even determining what, if any, guarantees can be made about privacy has become increasingly difficult.;Furthermore, the Edward Snowden leaks and other similar revelations have made it clear that if an opportunity exists to exploit or clandestinely monitor a device or system, there are likely adversaries working to do so. This has been shown to be the case from the highest level network activity to the lowest level device component firmware. To ensure privacy for a computer user, not only must one ensure network communication is protected from monitoring, but also that the private data was not compromised before it was transmitted in the first place. For example, anonymous and encrypted communication is of significantly diminished utility if an adversary has control of your hard drive firmware.;In this thesis, I look at how privacy for computer users has changed recently, from the highest to the lowest levels of communication in computing. A key contribution of this thesis is the introduction of a Networked Privacy Stack that considers security and privacy of information across multiple components of computation and communication. At the highest level, I look at communications across the internet, to applications such as encrypted Voice-over-IP and anonymity networks that shuffle general traffic to conceal network connections. I discuss shortcomings in these applications, and present practical improvements to each. This thesis also explores new methods for software attestation. I devise new methods for detecting attempted exfiltration of information via covert timing channels, and evaluate a new integrity measure to prevent malicious code from masquerading as legitimate, expected code. |
