Censorship Resistance as a Side-Effect

This position paper presents the following thought experiment: can we build communication protocols that (1) are sufficiently useful that they achieve widespread adoption as general-purpose communication mechanisms and (2) thwart censorship as a consequence of their design? We posit that a useful communication platform that is inherently resistant to traffic analysis, if widely adopted and used primarily for purposes not related to censorship circumvention, may be too politically and economically costly for a government to block.

The Eavesdropper\u27s Dilemma

This paper examines the problem of surreptitious Internet interception from the eavesdropper\u27s point of view. We introduce the notion of fidelity in digital eavesdropping. In particular, we formalize several kinds of network noise that might degrade fidelity, most notably confusion, and show that reliable network interception may not be as simple as previously thought or even always possible. Finally, we suggest requirements for high fidelity network interception, and show how systems that do not meet these requirements can be vulnerable to countermeasures, which in some cases can be performed entirely by a third party without the cooperation or even knowledge of the communicating parties

On the Reliability of Current Generation Network Eavesdropping Tools

This paper analyzes the problem of interception of Internet traffic from the eavesdropper\u27s point of view. We examine the reliability and accuracy of transcripts, and show that obtaining high fidelity transcripts is harder than previously assumed. Even in highly favorable situations, such as capturing unencrypted traffic using standard protocols, simple -- and entirely unilateral -- countermeasures are shown to be sufficient to prevent accurate traffic analysis in many Internet interception configurations. In particular, these countermeasures were successful against every available eavesdropping system we tested. Central to our approach is a new class of techniques that we call confusion, which, unlike cryptography or steganography, does not require cooperation by the communicating parties and, in some case, can be employed entirely by a third party not involved in the communication at all

Moving Targets: Geographically Routed Human Movement Networks

We introduce a new communication paradigm, Human-to-human Mobile Ad hoc Networking (HuManet), that exploits smartphone capabilities and human behavior to create decentralized networks for smartphone-to-smartphone message delivery. HuManets support stealth command-and-control messaging for mobile BotNets, covert channels in the presence of an observer who monitors all cellular communication, and distributed protocols for querying the state or content of targeted mobile devices. In this paper, we introduce techniques for constructing HumaNets and describe protocols for efficiently routing and addressing messages. In contrast to flooding or broadcast schemes that saturate the network and aggressively consume phone resources (e.g., batteries), our protocols exploit human mobility patterns to significantly increase communication efficiency while limiting the exposure of HuManets to mobile service providers. Our techniques leverage properties of smartphones – in particular, their highly synchronized clocks and ability to discern location information – to construct location profiles for each device. HuManets’ fully-distributed and heuristic-based routing protocols route messages towards phones with location profiles that are similar to those of the intended receiver, enabling efficient message delivery with limited effects to end-to-end latency

Security Protocols With Isotropic Channels

We investigate the security properties of isotropic channels, broadcast media in which a receiver cannot reliably determine whether a message originated from any particular sender and a sender cannot reliably direct a message away from any particular receiver. We show that perfect isotropism implies perfect (information-theoretic) secrecy, and that asymptotically close to perfect secrecy can be achieved on any channel that provides some (bounded) uncertainty as to sender identity. We give isotropic security protocols under both passive and active adversary models, and discuss the practicality of realizing isotropic channels over various media

100,000 prize jackpot. Call now!: Identifying the pertinent features of SMS spam

ABSTRACT Mobile SMS spam is on the rise and is a prevalent problem. While recent work has shown that simple machine learning techniques can distinguish between ham and spam with high accuracy, this paper explores the individual contributions of various textual features in the classification process. Our results reveal the surprising finding that simple is better: using the largest spam corpus of which we are aware, we find that using simple textual features is sufficient to provide accuracy that is nearly identical to that achieved by the best known techniques, while achieving a twofold speedup

Secure Network Provenance

This paper introduces secure network provenance (SNP), a novel technique that enables networked systems to explain to their operators why they are in a certain state – e.g., why a suspicious routing table entry is present on a certain router, or where a given cache entry originated. SNP provides network forensics capabilities by permitting operators to track down faulty or misbehaving nodes, and to assess the damage such nodes may have caused to the rest of the system. SNP is designed for adversarial settings and is robust to manipulation; its tamper-evident properties ensure that operators can detect when compromised nodes lie or falsely implicate correct nodes. We also present the design of SNooPy, a general-purpose SNP system. To demonstrate that SNooPy is practical, we apply it to three example applications: the Quagga BGP daemon, a declarative implementation of Chord, and Hadoop MapReduce. Our results indicate that SNooPy can efficiently explain state in an adversarial setting, that it can be applied with minimal effort, and that its costs are low enough to be practical

Sensor Network Security: More Interesting Than You Think

With the advent of low-power wireless sensor networks, a wealth of new applications at the interface of the real and digital worlds is emerging. A distributed computing platform that can measure properties of the real world, formulate intelligent inferences, and instrument responses, requires strong foundations in distributed computing, artificial intelligence, databases, control theory, and security. Before these intelligent systems can be deployed in critical infrastructures such as emergency rooms and powerplants, the security properties of sensors must be fully understood. Existing wisdom has been to apply the traditional security models and techniques to sensor networks. However, sensor networks are not traditional computing devices, and as a result, existing security models and methods are ill suited. In this position paper, we take the first steps towards producing a comprehensive security model that is tailored for sensor networks. Incorporating work from Internet security, ubiquitous computing, and distributed systems, we outline security properties that must be considered when designing a secure sensor network. We propose challenges for sensor networks – security obstacles that, when overcome, will move us closer to decreasing the divide between computers and the physical world