2015
Authors
Rodrigues, F; Oliveira, N; Barbosa, LS;
Publication
COMPUTER SCIENCE AND INFORMATION SYSTEMS
Abstract
Software reconfigurability became increasingly relevant to the architectural process due to the crescent dependency of modern societies on reliable and adaptable systems. Such systems are supposed to adapt themselves to surrounding environmental changes with minimal service disruption, if any. This paper introduces an engine that statically applies reconfigurations to (formal) models of software architectures. Reconfigurations are specified using a domain specific language-ReCooPLa-which targets the manipulation of software coordination structures, typically used in service-oriented architectures (soa). The engine is responsible for the compilation of ReCooPLa instances and their application to the relevant coordination structures. The resulting configurations are amenable to formal analysis of qualitative and quantitative (probabilistic) properties.
2015
Authors
Madeira, A; Martins, MA; Barbosa, LS; Hennicker, R;
Publication
FORMAL ASPECTS OF COMPUTING
Abstract
Hybrid logics, which add to the modal description of transition structures the ability to refer to specific states, offer a generic framework to approach the specification and design of reconfigurable systems, i.e., systems with reconfiguration mechanisms governing the dynamic evolution of their execution configurations in response to both external stimuli or internal performance measures. A formal representation of such systems is through transition structures whose states correspond to the different configurations they may adopt. Therefore, each node is endowed with, for example, an algebra, or a first-order structure, to precisely characterise the semantics of the services provided in the corresponding configuration. This paper characterises equivalence and refinement for these sorts of models in a way which is independent of (or parametric on) whatever logic (propositional, equational, fuzzy, etc) is found appropriate to describe the local configurations. A Hennessy-Milner like theorem is proved for hybridised logics.
2015
Authors
Oliveira, N; Silva, A; Barbosa, LS;
Publication
J. Internet Serv. Inf. Secur.
Abstract
2015
Authors
Oliveira, N; Barbosa, LS;
Publication
J. Softw. Eng. Res. Dev.
Abstract
2015
Authors
Oliveira, N; Barbosa, LS;
Publication
SCIENCE OF COMPUTER PROGRAMMING
Abstract
Software connectors encapsulate interaction patterns between services in complex, distributed service-oriented applications. Such patterns encode the interconnection between the architectural elements in a system, which is not necessarily fixed, but often evolves dynamically. This may happen in response to faults, degrading levels of QoS, new enforced requirements or the re-assessment of contextual conditions. To be able to characterise and reason about such changes became a major issue in the project of trustworthy software. This paper discusses what reconfiguration means within coordination-based models of software design. In these models computation and interaction are kept separate: components and services interact anonymously through specific connectors encoding the coordination protocols. In such a setting, of which Reo is a paradigmatic illustration, the paper introduces a model for connector reconfigurations, from both a structural and a behavioural perspective.
2015
Authors
Barbosa, M; Farshim, P;
Publication
FAST SOFTWARE ENCRYPTION, FSE 2014
Abstract
It is well known that the classical three-and four-round Feistel constructions are provably secure under chosen-plaintext and chosen-ciphertext attacks, respectively. However, irrespective of the number of rounds, no Feistel construction can resist related-key attacks where the keys can be offset by a constant. In this paper we show that, under suitable reuse of round keys, security under related-key attacks can be provably attained. Our modification is simpler and more efficient than alternatives obtained using generic transforms, namely the PRG transform of Bellare and Cash (CRYPTO 2010) and its random-oracle analogue outlined by Lucks (FSE 2004). Additionally we formalize Luck's transform and show that it does not always work if related keys are derived in an oracle-dependent way, and then prove it sound under appropriate restrictions.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.