Hugo Pacheco

Nuno Macedo, Hugo Pacheco

Many properties related to security or concurrency must be encoded as so-called hyperproperties, temporal properties that allow reasoning about multiple traces of a system. However, despite recent advances on model checking hyperproperties, there is still a lack of higher-level specification languages that can effectively support software engineering practitioners in verifying properties of this class at early stages of system design. Alloy is a lightweight formal method with a high-level specification language that is supported by automated analysis procedures, making it particularly well-suited for the verification of design models at early development stages. It does not natively support, however, the verification of hyperproperties. This work proposes HyperPardinus, a new model finding procedure that extends Pardinus -- the temporal logic backend of the Alloy language -- to automatically verify hyperproperties over relational models by relying on existing low-level model checkers for hyperproperties. It then conservatively extends Alloy to support the specification and automatic verification of hyperproperties over design models, as well as the visualization of (counter-)examples at a higher-level of abstraction. Evaluation shows that our approach enables modeling and finding (counter-)examples for complex hyperproperties with alternating quantifiers, making it feasible to address relevant scenarios from the state of the art.

José Carlos Bacelar Almeida, Manuel Barbosa, Karim Eldefrawy et al.

MPC-in-the-Head (MitH) is a general framework that allows constructing efficient Zero Knowledge protocols for general NP-relations from secure multiparty computation (MPC) protocols. In this paper we give the first machine-checked implementation of this transformation. We begin with an EasyCrypt formalization of MitH that preserves the modular structure of MitH and can be instantiated with arbitrary MPC protocols that satisfy standard notions of security, which allows us to leverage an existing machine-checked secret-sharing-based MPC protocol development. The resulting concrete ZK protocol is proved secure and correct in EasyCrypt. Using a recently developed code extraction mechanism for EasyCrypt we synthesize a formally verified implementation of the protocol, which we benchmark to get an indication of the overhead associated with our formalization choices and code extraction mechanism.

Hugo Pacheco, Nuno Macedo

Robotics is incredibly fun and is long recognized as a great way to teach programming, while drawing inspiring connections to other branches of engineering and science such as maths, physics or electronics. Although this symbiotic relationship between robotics and programming is perceived as largely beneficial, educational approaches often feel the need to hide the underlying complexity of the robotic system, but as a result fail to transmit the reactive essence of robot programming to the roboticists and programmers of the future. This paper presents ROSY, a novel language for teaching novice programmers through robotics. Its functional style is both familiar with a high-school algebra background and a materialization of the inherent reactive nature of robotic programming. Working at a higher-level of abstraction also teaches valuable design principles of decomposition of robotics software into collections of interacting controllers. Despite its simplicity, ROSY is completely valid Haskell code compatible with the ROS ecosystem. We make a convincing case for our language by demonstrating how non-trivial applications can be expressed with ease and clarity, exposing its sound functional programming foundations, and developing a web-enabled robot programming environment.