Biblio
Contrary to widespread assumption, dynamic RAM (DRAM), the main memory in most modern computers, retains its contents for several seconds after power is lost, even at room temperature and even if removed from a motherboard. Although DRAM becomes less reliable when it is not refreshed, it is not immediately erased, and its contents persist sufficiently for malicious (or forensic) acquisition of usable full-system memory images. We show that this phenomenon limits the ability of an operating system to protect cryptographic key material from an attacker with physical access to a machine. It poses a particular threat to laptop users who rely on disk encryption: we demonstrate that it could be used to compromise several popular disk encryption products without the need for any special devices or materials. We experimentally characterize the extent and predictability of memory retention and report that remanence times can be increased dramatically with simple cooling techniques. We offer new algorithms for finding cryptographic keys in memory images and for correcting errors caused by bit decay. Though we discuss several strategies for mitigating these risks, we know of no simple remedy that would eliminate them.
REMAN is a reputation management infrastructure for composite Web services. It supports the aggregation of client feedback on the perceived QoS of external services, using reputation mechanisms to build service rankings. Changes in rankings are pro-actively notified to composite service clients to enable self-tuning properties in their execution.
STONESOUP develops and demonstrates comprehensive, automated techniques that allow end users to securely execute software without basing risk mitigations on characteristics of provenance that have a dubious relationship to security. Existing techniques to find and remove software vulnerabilities are costly, labor-intensive, and time-consuming. Many risk management decisions are therefore based on qualitative and subjective assessments of the software suppliers' trustworthiness. STONESOUP develops software analysis, confinement, and diversification techniques so that non-experts can transform questionable software into more secure versions without changing the behavior of the programs.