301 research outputs found
Self-Adaptation and Secure Information Flow in Multiparty Structured Communications: A Unified Perspective
We present initial results on a comprehensive model of structured
communications, in which self- adaptation and security concerns are jointly
addressed. More specifically, we propose a model of self-adaptive, multiparty
communications with secure information flow guarantees. In this model, security
violations occur when processes attempt to read or write messages of
inappropriate security levels within directed exchanges. Such violations
trigger adaptation mechanisms that prevent the violations to occur and/or to
propagate their effect in the choreography. Our model is equipped with local
and global mechanisms for reacting to security violations; type soundness
results ensure that global protocols are still correctly executed, while the
system adapts itself to preserve security.Comment: In Proceedings BEAT 2014, arXiv:1408.556
Combining behavioural types with security analysis
Today's software systems are highly distributed and interconnected, and they
increasingly rely on communication to achieve their goals; due to their
societal importance, security and trustworthiness are crucial aspects for the
correctness of these systems. Behavioural types, which extend data types by
describing also the structured behaviour of programs, are a widely studied
approach to the enforcement of correctness properties in communicating systems.
This paper offers a unified overview of proposals based on behavioural types
which are aimed at the analysis of security properties
Reversible Multiparty Sessions with Checkpoints
Reversible interactions model different scenarios, like biochemical systems
and human as well as automatic negotiations. We abstract interactions via
multiparty sessions enriched with named checkpoints. Computations can either go
forward or roll back to some checkpoints, where possibly different choices may
be taken. In this way communications can be undone and different conversations
may be tried. Interactions are typed with global types, which control also
rollbacks. Typeability of session participants in agreement with global types
ensures session fidelity and progress of reversible communications.Comment: In Proceedings EXPRESS/SOS 2016, arXiv:1608.0269
A gentle introduction to multiparty asynchronous session types
This article provides a gentle introduction to multiparty session types, a class of behavioural types specifically targeted at describing protocols in distributed systems based on asynchronous communication. The type system ensures well-typed processes to enjoy non-trivial properties, including communication safety, protocol fidelity, as well as progress. The adoption of multiparty session types can positively affect the whole software lifecycle, from design to deployment, improving software reliability and reducing its development costs
Parameterized Concurrent Multi-Party Session Types
Session types have been proposed as a means of statically verifying
implementations of communication protocols. Although prior work has been
successful in verifying some classes of protocols, it does not cope well with
parameterized, multi-actor scenarios with inherent asynchrony. For example, the
sliding window protocol is inexpressible in previously proposed session type
systems. This paper describes System-A, a new typing language which overcomes
many of the expressiveness limitations of prior work. System-A explicitly
supports asynchrony and parallelism, as well as multiple forms of
parameterization. We define System-A and show how it can be used for the static
verification of a large class of asynchronous communication protocols.Comment: In Proceedings FOCLASA 2012, arXiv:1208.432
Lightening Global Types
Global session types prevent participants from waiting for never coming
messages. Some interactions take place just for the purpose of informing
receivers that some message will never arrive or the session is terminated. By
decomposing a big global type into several light global types, one can avoid
such kind of redundant interactions. Lightening global types gives us cleaner
global types, which keep all necessary communications. This work proposes a
framework which allows to easily decompose global types into light global
types, preserving the interaction sequences of the original ones but for
redundant interactions.Comment: In Proceedings PLACES 2014, arXiv:1406.331
Explicit connection actions in multiparty session types
This work extends asynchronous multiparty session types (MPST) with explicit connection actions to support protocols with op- tional and dynamic participants. The actions by which endpoints are connected and disconnected are a key element of real-world protocols that is not treated in existing MPST works. In addition, the use cases motivating explicit connections often require a more relaxed form of mul- tiparty choice: these extensions do not satisfy the conservative restric- tions used to ensure safety in standard syntactic MPST. Instead, we de- velop a modelling-based approach to validate MPST safety and progress for these enriched protocols. We present a toolchain implementation, for distributed programming based on our extended MPST in Java, and a core formalism, demonstrating the soundness of our approach. We discuss key implementation issues related to the proposed extensions: a practi- cal treatment of choice subtyping for MPST progress, and multiparty correlation of dynamic binary connections
Parallel Monitors for Self-adaptive Sessions
The paper presents a data-driven model of self-adaptivity for multiparty
sessions. System choreography is prescribed by a global type. Participants are
incarnated by processes associated with monitors, which control their
behaviour. Each participant can access and modify a set of global data, which
are able to trigger adaptations in the presence of critical changes of values.
The use of the parallel composition for building global types, monitors and
processes enables a significant degree of flexibility: an adaptation step can
dynamically reconfigure a set of participants only, without altering the
remaining participants, even if the two groups communicate.Comment: In Proceedings PLACES 2016, arXiv:1606.0540
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