In this paper we introduce a novel approach to the speciication of real-time behaviour with process algebras. In contrast to the usual pattern, involving a xed, measurable, and global notion of time, we suggest to represent real-time constraints indirectly through uninterpreted clocks enforcing broadcast synchronization between processes. Our approach advocates the use of asynchronous process a...

The information security community has long debated the exact definition of the term ‘security’. Even if we focus on the more specific notion of confidentiality the precise definition remains controversial. In their seminal paper [4], Goguen and Meseguer took an important step towards a formalisation of the notion of absence of information flow with the concept of non-interference. This too was...

An axiom system ACP lm is presented as a variant of the process algebra ACP (Algebra of Communicating Processes). The acronym ACP lm stands for ACP with abstraction, extended with operators and axioms for language matching. Language matching is a technique based on trace information for labelling and cutting oo process terms that do not match some given trace (or set of traces). It is shown tha...

While the technologies for generation of electronic signatures are well-established in public-key infrastructures, the validation of electronic signatures still shows some open problems. The verification of the validity of an electronic signature requires high degrees of diligence, time and effort for the local configuration and management of trusted certificates and their revocation status. A ...

PAM is a general proof tool for process algebras. It allows users to deene their own calculi and then perform algebraic style proofs in these calculi by directly manipulating process terms. The logic that PAM implements is equational logic plus recursion, with some features tailored to the particular requirements of process algebras. Equational reasoning is implemented by rewriting, while recur...

We investigate different forms of termination in timed process algebras. The integrated framework of discrete and dense time, relative and absolute time process algebras is extended with forms of successful and unsuccessful termination. The different algebras are interrelated by embed dings and conservative extensions.

In 10] Groote and Springintveld incorporated several model-oriented techniques { such as invariants, matching criteria, state mappings { in the process-algebraic framework of CRL for structuring and simplifying protocol veriications. In this paper, we formalise these extensions in Coq, which is a proof development tool based on type theory. In the updated framework, the length of proof construc...

We present a first-order extension of the algebraic theory about processes known as ACP and its main models. Useful predicates on processes, such as deadlock freedom and determinism, can be added to this theory through first-order definitional extensions. Model theory is used to analyse the discrepancies between identity in the models of the first-order extension of ACP and bisimilarity of the ...

3 Axiomatisation of the Binary Kleene Star 15 3.1 Preliminaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2 Completeness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 Irredundancy of the Axioms . . . . . . . . . . . . . . . . . . . . . . . 24 3.4 Negative Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.5 Extensions of BPA∗(A...

We discern three non-classical truth values, and define a five-valued propositional logic. We combine this logic with process algebra via conditional composition (i.e., if-then-else-). In particular, the choice operation (+) is regarded as a special case of conditional composition. We present an operational semantics in SOS-style and some completeness results.  2001 Elsevier Science B.V. All r...