Scientific Foundations

Access control policies specify which users may perform which actions on which resources within which environments. Defective policies may have serious impacts, allowing unintended access (e.g., bank account withdrawals by a stranger) or preventing critical legitimate access (e.g., a doctor cannot view her patient's x-ray). As computer systems become more complex, policy defects have become more common.

The cybercriminal community is inarguably more organized, better resourced and more motivated than ever to perpetrate massive-scale computer infections across the Internet. The malware distribution systems that they control and operate are characterized by their use of highly specialized suppliers and commoditized malware services.

The proliferation and increasing sophistication of censorship warrants continuing efforts to develop tools to evade it. Yet, designing effective mechanisms for censorship resistance ultimately depends on accurate models of the capabilities of censors, as well as how those capabilities will likely evolve. In contrast to more established disciplines within security, censorship resistance is relatively nascent, not yet having solid foundations for understanding censor capabilities or evaluating the effectiveness of evasion technologies.

The essence of information assurance resides in the ability of the legitimate communication parties to establish and maintain an advantage over their adversary. Most often, such an advantage is in the form of a secret key. The high costs associated with standard key establishment protocols motivate the recent surge of less conventional protocols, which derive the legitimate parties' advantage from physical features (the adversary may have a worse channel than the legitimate receiver) or from correlated sources of randomness (accelerometer readings when two devices are shaken together).

Cloud computing poses significant risks to the security of client data. Virtual Machine Monitors (VMMs) that underlie cloud systems typically have all-powerful administrative domains that can be exploited or misused to snoop on client virtual machines (VMs) and steal/modify their data. Moreover, although virtual machine technology enables several novel security services that clients may wish to use, such services are privileged and must be implemented within the administrative domain.