Smart Types for Smart Contracts Validation

• Autor(a) principal: Corte, Ronaldo Ludgero Abreu da
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/161077
• topic: Smart Contracts; Blockchain; programming Languages; safety; Soundness; Typechecking; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática

The notion of Smart Contracts consist in describing agreements between two or more parties that can be automatically enforced without a trusted intermediary. Smart Con- tracts run on a very specific network of peers called Blockchain, a a digitally distributed, decentralized, public ledger that exists across a network. Potential conflicts are resolved by the network’s consensus protocol. The Blockchain [26] is immutable, this means that once a Smart Contract is deployed on the Blockchain it cannot be amended. This immutability (despite being one important selling point of Smart Contracts) leave no room for mistakes in their implementation. Many contracts are hard to implement correctly and bugs and vulnerabilities can be exploited for erroneous or even fraudulent behaviour. The countless advantages and applications of Smart contracts are constantly increas- ing their popularity. This added to the fact that Smart Contracts manipulate resources with monetary value is bringing a lot of attention to attackers. There are a lot of infamous Smart Contracts attacks, the DAO Attack per example drained millions of dollars in Ether (cryptocurrency of Ethereum). Mainstream tools used to develop distributed Smart Contracts do not address these requirements. Consequently, many vulnerabilities of these contracts are known and can be exploited. In order to help developers to design safer contracts that follow their protocols and specifications we propose a language integrated with assertions and a static behavioural type system able of protecting resources and enforce usage protocols to ensure the safety and soundness in Smart Contracts execution. Since proof assistants are too demanding for most developers, there is a need for automatic tools well integrated with programming languages. Therefore, we joined our language with a model-checker to discharge to it the quantitative assertions during the compilation process. In short, we provided a translation of the types and assertions to an automaton in the format of Cubicle’s (model checker) input language and used this one to conduct Software Verification.