Learn More
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)
Anonymous communication (AC) protocols such as the widely used Tor network have been designed to provide anonymity over the Internet to their participating users. While AC protocols have been the subject of several security and anonymity analyses in the last years, there still does not exist a framework for analyzing complex systems, such as Tor, and their(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)
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)
Cryptographic protocols are commonly designed and their security proven under the assumption that the protocol parties have access to perfect (uniform) randomness. Physical randomness sources deployed in practical implementations of these protocols often fall short in meeting this assumption, but instead provide only a steady stream of bits with certain(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)
  • 1