A formal treatment of the role of verified compilers in secure computation

• Published in: Journal of logical and algebraic methods in programming Vol. 125; p. 100736
• Main Authors: Bacelar Almeida, José Carlos, Barbosa, Manuel, Barthe, Gilles, Pacheco, Hugo, Pereira, Vitor, Portela, Bernardo
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.02.2022
• Subjects: Certified compilation; Computer-aided cryptography; EasyCrypt; Formal verification; Secure compilation; Secure multiparty computation; Secure multiparty computation; Secure compilation; Computer-aided cryptography; EasyCrypt; Certified compilation; Formal verification
• ISSN: 2352-2208
• DOI: 10.1016/j.jlamp.2021.100736

Secure multiparty computation (SMC) allows for complex computations over encrypted data. Privacy concerns for cloud applications makes this a highly desired technology and recent performance improvements show that it is practical. To make SMC accessible to non-experts and empower its use in varied applications, many domain-specific compilers are being proposed. We review the role of these compilers and provide a formal treatment of the core steps that they perform to bridge the abstraction gap between high-level ideal specifications and efficient SMC protocols. Our abstract framework bridges this secure compilation problem across two dimensions: 1) language-based source- to target-level semantic and efficiency gaps, and 2) cryptographic ideal- to real-world security gaps. We link the former to the setting of certified compilation, paving the way to leverage long-run efforts such as CompCert in future SMC compilers. Security is framed in the standard cryptographic sense. Our results are supported by a machine-checked formalisation carried out in EasyCrypt.