Secure Mobile Agent from Leakage-Resilient Proxy Signatures

A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator) to delegate its signing right to another entity (proxy) to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems

Privacy-Protecting Energy Management Unit through Model-Distribution Predictive Control

The roll-out of smart meters in electricity networks introduces risks for consumer privacy due to increased measurement frequency and granularity. Through various Non-Intrusive Load Monitoring techniques, consumer behavior may be inferred from their metering data. In this paper, we propose an energy management method that reduces energy cost and protects privacy through the minimization of information leakage. The method is based on a Model Predictive Controller that utilizes energy storage and local generation, and that predicts the effects of its actions on the statistics of the actual energy consumption of a consumer and that seen by the grid. Computationally, the method requires solving a Mixed-Integer Quadratic Program of manageable size whenever new meter readings are available. We simulate the controller on generated residential load profiles with different privacy costs in a two-tier time-of-use energy pricing environment. Results show that information leakage is effectively reduced at the expense of increased energy cost. The results also show that with the proposed controller the consumer load profile seen by the grid resembles a mixture between that obtained with Non-Intrusive Load Leveling and Lazy Stepping.Comment: Accepted for publication in IEEE Transactions on Smart Grid 2017, special issue on Distributed Control and Efficient Optimization Methods for Smart Gri

Black-Box Constructions of Signature Schemes in the Bounded Leakage Setting

To simplify the certificate management procedures, Shamir introduced the concept of identity-based cryptography (IBC). However, the key escrow problem is inherent in IBC. To get rid of it, Al-Riyami and Paterson introduced in 2003 the notion of certificateless cryptography (CLC). However, if a cryptosystem is not perfectly implemented, adversaries would be able to obtain part of the system\u27s secret state via side-channel attacks, and thus may break the system. This is not considered in the security model of traditional cryptographic primitives. Leakage-resilient cryptography was then proposed to prevent adversaries from doing so. There are fruitful works on leakage-resilient encryption schemes, while there are not many on signature schemes in the leakage setting. In this work, we review the folklore generic constructions of identity-based signature and certificateless signature, and show that if the underlying primitives are leakage-resilient, so are the resulting identity-based signature scheme and certificateless signature scheme. The leakage rate follows the minimum one of the underlying primitives. We also show some instantiations of these generic constructions

Pre- and post-race intestinal microbiota in long-distance sled dogs and associations with performance

Although our understanding of the role of the gut microbiota in different diseases is improving, our knowledge regarding how the gut microbiota affects functioning in healthy individuals is still limited. Here, we hypothesize that the gut microbiota could be associated with sled dog endurance-race performance. We investigated the gut microbiota in 166 fecal samples from 96 Alaskan Huskies, representing 16 teams participating in the 2016 Femund Race (400 km) in Norway, relating the microbiota composition to performance and metadata derived from questionnaires. For 16S rRNA gene sequencing-derived compositional data, we found a strong negative association between Enterobacteriaceae (dysbiosis-associated) and Clostridium hiranonis (normobiosis-associated). The teams with the best performances showed both the lowest levels of dysbiosis-associated bacteria prior to the race and the lowest change (decrease) in these bacteria after the race. Taken together, our results support the hypothesis that normobiosis-associated bacteria are involved in resilience mechanisms, potentially preventing growth of Enterobacteriaceae during the race.publishedVersio