A Calculus of Mobile Resources

We introduce a calculus of Mobile Resources (MR) tailored for the design and analysis of systems containing mobile, possibly nested, computing devices that may have resource and access constraints, and which are not copyable nor modifiable per se. We provide a reduction as well as a labelled transition semantics and prove a correspondence be- tween barbed bisimulation congruence and a higher-order bisimulation. We provide examples of the expressiveness of the calculus, and apply the theory to prove one of its characteristic properties

An algebra of behavioural types

Special thanks to Gérard Boudol, Ilaria Castellani, Silvano Dal Zilio, and Massimo Merro, for fruitful discussions and careful reading of parts of this document. Several anonymous referees made useful comments.We propose a process algebra, the Algebra of Behavioural Types, as a language for typing concurrent objects. A type is a higher-order labelled transition system that characterises all possible life cycles of a concurrent object. States represent interfaces of objects; state transitions model the dynamic change of object interfaces. Moreover, a type provides an internal view of the objects that inhabits it: a synchronous one, since transitions correspond to message reception. To capture this internal view of objects we define a notion of bisimulation, strong on labels and weak on silent actions. We study several algebraic laws that characterise this equivalence, and obtain completeness results for image-finite types.publishersversionpublishe

Responsible AI and Analytics for an Ethical and Inclusive Digitized Society

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On Equivalences, Metrics, and Computational Indistinguishability

The continuous technological progress and the constant growing of information flow we observe every day, brought us an urgent need to find a way to defend our data from malicious intruders; cryptography is the field of computer science that deals with security and studies techniques to protect communications from third parties, but in the recent years there has been a crisis in proving the security of cryptographic protocols, due to the exponential increase in the complexity of modeling proofs. In this scenario we study interactions in a typed lambda-calculus properly defined to fit well into the key aspects of a cryptographic proof: interaction, complexity and probability. This calculus, RSLR, is an extension of Hofmann's SLR for probabilistic polynomial time computations and it is perfect to model cryptographic primitives and adversaries. In particular, we characterize notions of context equivalence and context metrics, when defined on linear contexts, by way of traces, making proofs easier. Furthermore we show how to use this techniqe to obtain a proof methodology for computational indistinguishability, a key notion in modern cryptography; finally we give some motivating examples of concrete cryptographic schemes

Proceedings of the Seventh Congress of the European Society for Research in Mathematics Education

International audienceThis volume contains the Proceedings of the Seventh Congress of the European Society for Research in Mathematics Education (ERME), which took place 9-13 February 2011, at Rzeszñw in Poland

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp