• Publications
  • Influence
CAPTCHA: Using Hard AI Problems for Security
TLDR
We introduce captcha, an automated test that humans can pass, but current computer programs can't pass: any program that has high success over a captcha can be used to solve an unsolved Artificial Intelligence (AI) problem. Expand
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Secure Human Identification Protocols
TLDR
In this paper, we provide definitions of what we believe to be reasonable goals for secure human identification. Expand
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Shadow: Running Tor in a Box for Accurate and Efficient Experimentation
TLDR
We present the design and implementation of Shadow, an architecture for efficiently running accurate Tor experiments on a single machine. Expand
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Analysis of genetic diversity through population history
TLDR
The idea that diversity in the population of a genetic algorithm affects the algorithm's search efficiency is widely accepted. Expand
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How much anonymity does network latency leak?
TLDR
We present two attacks on low-latency anonymity schemes using this information. Expand
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k-anonymous message transmission
TLDR
We show that there exist simple protocols which are k-anonymous for both the sender and the receiver in a model where a polynomial time adversary can see all traffic in the network and can control up to a constant fraction of the participants. Expand
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Scalable onion routing with torsk
TLDR
We introduce Torsk, a structured peer-to-peer low-latency anonymity protocol that decreases the bandwidth cost of relay selection and maintenance from quadratic to quasilinear while introducing no new attacks on the anonymity provided by Tor, and no additional delay to connections made via Tor. Expand
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Routing around decoys
TLDR
We show that a routing capable adversary can enumerate the participating routers implementing these protocols; can successfully avoid sending traffic along routes containing these routers with little or no adverse effects. Expand
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Vampire Attacks: Draining Life from Wireless Ad Hoc Sensor Networks
TLDR
This paper explores resource depletion attacks at the routing protocol layer, which permanently disable networks by quickly draining nodes' battery power. Expand
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Keep your friends close: Incorporating trust into social network-based Sybil defenses
TLDR
In this paper we introduce several designs to tune the performance of Sybil defenses by accounting for differential trust in social graphs and modeling these trust values by biasing random walks performed on these graphs. Expand
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