Paul Grubbs, Cornell Tech; Anurag Khandelwal, Yale University; Marie-Sarah Lacharité, Royal Holloway, University of London; Lloyd Brown, University of California, Berkeley (and Cornell alumnus); Lucy Li, Cornell Tech; Rachit Agarwal, Cornell University; Thomas Ristenpart, Cornell Tech
Abstract: We present PANCAKE, the first system to protect key-value stores from access pattern leakage attacks with small constant factor bandwidth overhead. PANCAKE uses a new approach, that we call frequency smoothing, to transform plaintext accesses into uniformly distributed encrypted accesses to an encrypted data store. We show that frequency smoothing prevents access pattern leakage attacks by passive persistent adversaries in a new formal security model. We integrate PANCAKE into three key-value stores used in production clusters, and demonstrate its practicality: on standard benchmarks, PANCAKE achieves 229× better throughput than non-recursive Path ORAM — within 3–6× of insecure baselines for these key-value stores.
Emily Tseng, Cornell University; Rosanna Bellini, Open Lab, Newcastle University; Nora McDonald, University of Maryland, Baltimore County; Matan Danos, Weizmann Institute of Science; Rachel Greenstadt, New York University; Damon McCoy, New York University; Nicola Dell, Cornell Tech; Thomas Ristenpart, Cornell Tech
Abstract: Abusers increasingly use spyware apps, account compromise, and social engineering to surveil their intimate partners, causing substantial harms that can culminate in violence. This form of privacy violation, termed intimate partner surveillance (IPS), is a profoundly challenging problem to address due to the physical access and trust present in the relationship between the target and attacker. While previous research has examined IPS from the perspectives of survivors, we present the first measurement study of online forums in which (potential) attackers discuss IPS strategies and techniques. In domains such as cybercrime, child abuse, and human trafficking, studying the online behaviors of perpetrators has led to better threat intelligence and techniques to combat attacks. We aim to provide similar insights in the context of IPS. We identified five online forums containing discussion of monitoring cellphones and other means of surveilling an intimate partner, including three within the context of investigating relationship infidelity. We perform a mixed-methods analysis of these forums, surfacing the tools and tactics that attackers use to perform surveillance. Via qualitative analysis of forum content, we present a taxonomy of IPS strategies used and recommended by attackers, and synthesize lessons for technologists seeking to curb the spread of IPS.
Both paper links (above) feature presentation videos.
"The Tools and Tactics Used in Intimate Partner Surveillance" also won third place in the 2020 Internet Defense Prize competition.