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The energy industry has recently begun using smart meters to take fine-grained readings of energy usage. These smart meters enable flexible time-of-use billing, forecasting, and demand response, but they also raise serious user privacy concerns. We propose a novel technique for provably hiding sensitive power consumption information in the overall power(More)
In this paper we present MATor: a framework for rigorously assessing the degree of anonymity in the Tor network. The framework explicitly addresses how user anonymity is impacted by real-life characteristics of actually deployed Tor, such as its path selection algorithm, Tor consensus data, and the preferences and the connections of the user. The anonymity(More)
We introduce delegatable functional signatures (DFS) which support the delegation of signing capabilities to another party, called the evaluator, with respect to a functionality F. In a DFS, the signer of a message can choose an evaluator, specify how the evaluator can modify the signature without voiding its validity, allow additional input and decide how(More)
Protecting individuals' privacy in online communications has become a challenge of paramount importance. To this end, anonymous communication (AC) protocols such as the widely used Tor network have been designed to provide anonymity to their participating users. While AC protocols have been the subject of several security and anonymity analyses in the last(More)
Functional encryption, as introduced by Boneh, Sahai, and Waters (TCC'11), generalizes public-key encryption systems to include functional decryption capabilities. Recently, Boyle et al. as well as Bellare and Fuchsbauer (both PKC'14) formalized analogous notions for signature schemes. Here we discuss that both their notions are limited in terms of(More)
Protecting individuals' privacy in online communications has become a challenge of paramount importance. To this end, anonymous communication (AC) protocols such as the widely used Tor network have been designed to provide anonymity to their participating users. While AC protocols have been the subject of several security and anonymity analyses in the last(More)
Delegation of signing rights is a central problem in security. Whereas delegating by giving power of attorney is well studied and digitally realized via delegatable anonymous credentials, directly delegating signing possibilities without the need for an external logic, can be done via malleable signature schemes. However, the existing schemes do not allow(More)
Recently, the live-monitor MATor for formally analyzing user anonymity within the Tor network has been proposed (CCS'14). However, this monitor only considers adversaries that compromise part of the Tor network itself, not Internet infrastructural adversaries. In this work we present a formal technique for analyzing Tor against malicious or overly curious(More)