Abstract
Providing public services through the internet is an effective approach towards an encompassing number of citizens being covered by them and for cost reduction. However, the fast development of this area has fostered discussion and legislation regarding information security and trustworthiness. In addition to security mechanisms for data processed and stored internally, service providers must ensure that data exchanged between their servers and citizens are not intercepted or modified when traversing heterogeneous and uncontrolled networks. Moreover, such institutions should provide means enabling the citizen to verify the authenticity of the services offered. In this way, the present work provides a comprehensive overview regarding the security posture of Portuguese public institutions in their online services. It consists of non-invasive robustness evaluation of the deployed solutions for end-to-end data encryption and the correct use of digital certificates. As a result, we provide some recommendations aiming to enhance the current panorama in the majority of the 111 online services considered in this study.

Abstract

Abstract

Abstract
VirtuosoNext (TM) is a distributed real-time operating system (RTOS) featuring a generic programming model dubbed Interacting Entities. This paper focuses on these interactions, implemented as so-called Hubs. Hubs act as synchronisation and communication mechanisms between the application tasks and implement the services provided by the kernel as a kind of Guarded Protected Action with a well defined semantics. While the kernel provides the most basic services, each carefully designed, tested and optimised, tasks are limited to this handful of basic hubs, leaving the development of more complex synchronization and communication mechanisms up to application specific implementations. In this work we investigate how to support a programming paradigm to compositionally build new services, using notions borrowed from the Reo coordination language, and relieving tasks from coordination aspects while delegating them to the hubs. We formalise the semantics of hubs using an automata model, identify the behaviour of existing hubs, and propose an approach to build new hubs by composing simpler ones. We also provide tools and methods to analyse and simplify hubs under our automata interpretation. In a first experiment several hub interactions are combined into a single more complex hub, which raises the level of abstraction and contributes to a higher productivity for the programmer. Finally, we investigate the impact on the performance by comparing different implementations on an embedded board.

Abstract
Building and maintaining complex systems requires good software engineering practices, including code modularity and reuse. The same applies in the context of coordination of complex component-based systems. This paper investigates how to verify properties of complex coordination patterns built hierarchically, i.e., built from composing blocks that are in turn built from smaller blocks. Most existing approaches to verify properties flatten these hierarchical models before the verification process, losing the hierarchical structure. We propose an approach to verify hierarchical models using containers as actions; more concretely, containers interacting with their neighbours. We present a dynamic modal logic tailored for hierarchical connectors, using Reo and Petri Nets to illustrate our approach. We realise our approach via a prototype implementation available online to verify hierarchical Reo connectors, encoding connectors and formulas into mCRL2 specifications and formulas.

Abstract