Clara Bertolissi

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Introduced at the end of the nineties, the Rewriting Calculus (ρ-calculus, for short) is a simple calculus that fully integrates term-rewriting and λ-calculus. The rewrite rules, acting as elaborated abstractions, their application and the obtained structured results are first class objects of the calculus. The evaluation mechanism, generalizing(More)
In large, and often distributed, environments, where access control information may be shared across multiple sites, the combination of individual specifications in order to define a coherent access control policy is of fundamental importance. In order to ensure non-ambiguous behaviour, formal languages, often relying on firstorder logic, have been(More)
Despite the widespread adoption of Role-based Access Control (RBAC) models, new access control models are required for new applications for which RBAC may not be especially well suited and for which implementations of RBAC do not enable properties of access control policies to be adequately defined and proven. To address these issues, we propose a form of(More)
The last few years have seen the development of the rewriting calculus (or rhocalculus, ρCal) that extends first order term rewriting and λ-calculus. The integration of these two latter formalisms has been already handled either by enriching first-order rewriting with higher-order capabilities, like in the Combinatory Reduction Systems, or by adding to(More)
We propose an access control model that takes into account the specific behaviour of distributed, highly dynamic environments, and describe their representation using an algebraic-functional framework. The declarative nature of the model facilitates the analysis of policies, and direct implementations for access control checking even when resources and(More)
The graph rewriting calculus is an extension of the ρ-calculus, handling graph like structures rather than simple terms. The calculus over terms is naturally generalized by using unification constraints in addition to the standard ρ-calculus matching constraints. The transformations are performed by explicit application of rewrite rules as first class(More)