A coalgebraic perspective on logical interpretations

In Computer Science stepwise refinement of algebraic specifications is a well-known formal methodology for rigorous program development. This paper illustrates how techniques from Algebraic Logic, in particular that of interpretation, understood as a multifunction that preserves and reflects logical consequence, capture a number of relevant transformations in the context of software design, reuse, and adaptation, difficult to deal with in classical approaches. Examples include data encapsulation and the decomposition of operations into atomic transactions. But if interpretations open such a new research avenue in program refinement, (conceptual) tools are needed to reason about them. In this line, the paper’s main contribution is a study of the correspondence between logical interpretations and morphisms of a particular kind of coalgebras. This opens way to the use of coalgebraic constructions, such as simulation and bisimulation, in the study of interpretations between (abstract) logics.Fundação para a Ciência e a Tecnologia (FCT

Generic Side-Channel Distinguishers: Improvements and Limitations

The goal of generic side-channel distinguishers is to allow key recoveries against any type of implementation, under minimum assumptions on the underlying hardware. Such distinguishers are particularly interesting in view of recent technological advances. Indeed, the traditional leakage models used in side-channel attacks, based on the Hamming weight or distance of the data contained in an implementation, are progressively invalidated by the increased variability in nanoscale electronic devices. In this paper, we consequently provide two contributions related to the application of side-channel analysis against emerging cryptographic implementations. First, we describe a new statistical test that is aimed to be generic and efficient when exploiting high-dimensional leakages. The proposed distinguisher is fully non-parametric. It formulates the leakage distributions using a copula and discriminates keys based on the detection of an “outlier behavior”. Next, we provide experiments putting forward the limitations of generic side-channel analysis in advanced scenarios, where leaking devices are protected with countermeasures. Our results exhibit that all non-profiled attacks published so far can sometimes give a false sense of security, due to incorrect leakage models. That is, there exists settings in which an implementation is secure against such non-profiled attacks and can be defeated with profiling. This confirms that the evaluations of cryptographic implementations should always consider profiling, as a worst case scenario

Technical means using by Customs administration of the Czech Republic to detection of narcotic and psychoactive drugs.

Autor v úvodu své práce krátce hodnotí vývoj problematiky užívání a zneužívání omamných a psychotropních látek na našem území a popisuje jednotlivé technické prostředky používané v minulosti a současnosti k jejich vyhledávání a detekci. Cílem práce je vymezení způsobu použití technických prostředků v praxi, vhodnosti jejich použití v konkrétních podmínkách výkonu služby a nové trendy ve vývoji a využití těchto prostředků