Robust and Efficient Approaches to Evaluating Side Channel and Fault Attack Resilience

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Hubs for VirtuosoNext: Online verification of real-time coordinators

Publication . Cledou, Guillermina; Proenca, Jose; Sputh, Bernhard H.C.; Verhulst, Eric

VirtuosoNext is a distributed real-time operating system (RTOS) fea- turing a generic programming model dubbed Interacting Entities. This pa- per 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. While the kernel provides the most basic services, each carefully designed, tested and opti- mised, tasks are limited to this handful of basic hubs, leaving the development of more complex mechanisms up to application specific implementations. This work presents a toolset that supports the building of new services compositionally, using notions borrowed from the Reo coordination language, on which the developer can delegate coordination-related duties. This toolset uses a formal compositional semantics for hubs that captures dataflow and time, formalising the behaviour of existing hubs, and allowing the defini- tion of new ones. Furthermore, it enables the analysis and verification of hubs under our automata interpretation, including time-sensitive behaviour via the Uppaal model checker, usable on http://arcatools.org/hubs. We illustrate the proposed tools and methods by verifying key properties on different interaction scenarios between tasks and a composed hub.

2021-03-01Journal article

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Implementing Hybrid Semantics: From Functional to Imperative

Publication . Goncharov, Sergey; Neves, Renato; Proenca, José

Hybrid programs combine digital control with differential equations, and naturally appear in a wide range of application domains, from biology and control theory to real-time software engineering. The entanglement of discrete and continuous behaviour inherent to such programs goes beyond the established computer science foundations, producing challenges related to e.g. infinite iteration and combination of hybrid behaviour with other effects. A systematic treatment of hybridness as a dedicated computational effect has emerged recently. In particular, a generic idealized functional language HybCore with a sound and adequate operational semantics has been proposed. The latter semantics however did not provide hints to implementing HybCore as a runnable language, suitable for hybrid system simulation (e.g. the semantics features rules with uncountably many premises). We introduce an imperative counterpart of HybCore, whose semantics is simpler and runnable, and yet intimately related with the semantics of HybCore at the level of hybrid monads. We then establish a corresponding soundness and adequacy theorem. To attest that the resulting semantics can serve as a firm basis for the implementation of typical tools of programming oriented to the hybrid domain, we present a web-based prototype implementation to evaluate and inspect hybrid programs, in the spirit of GHCi for Haskell and UTop for OCaml. The major asset of our implementation is that it formally follows the operational semantic rules.

2020Conference object

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Work-In-Progress: a DSL for the safe deployment of Runtime Monitors in Cyber-Physical Systems

Publication . Spilere Nandi, Giann; Pereira, David; Proenca, José; Tovar, Eduardo

Guaranteeing that safety-critical Cyber-Physical Systems (CPS) do not fail upon deployment is becoming an even more complicated task with the increased use of complex software solutions. To aid in this matter, formal methods (rigorous mathematical and logical techniques) can be used to obtain proofs about the correctness of CPS. In such a context, Runtime Verification has emerged as a promising solution that combines the formal specification of properties to be validated and monitors that perform these validations during runtime. Although helpful, runtime verification solutions introduce an inevitable overhead in the system, which can disrupt its correct functioning if not safely employed. We propose the creation of a Domain Specific Language (DSL) that, given a generic CPS, 1) verifies if its real- time scheduling is guaranteed, even in the presence of coupled monitors, and 2) implements several verification conditions for the correct-by-construction generation of monitoring architectures. To achieve it, we plan to perform statical verifications, derived from the available literature on schedulability analysis, and powered by a set of semi-automatic formal verification tools.

2020Conference object

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