Extracting smart contracts tested and verified in Coq

TY - GEN

T1 - Extracting smart contracts tested and verified in Coq

AU - Annenkov, Danil

AU - Milo, Mikkel

AU - Nielsen, Jakob Botsch

AU - Spitters, Bas

PY - 2021/1

Y1 - 2021/1

N2 - We implement extraction of Coq programs to functional languages based on MetaCoq's certified erasure. As part of this, we implement an optimisation pass removing unused arguments. We prove the pass correct wrt. a conventional call-by-value operational semantics of functional languages. We apply this to two functional smart contract languages, Liquidity and Midlang, and to the functional language Elm. Our development is done in the context of the ConCert framework that enables smart contract verification. We contribute a verified boardroom voting smart contract featuring maximum voter privacy such that each vote is kept private except under collusion of all other parties. We also integrate property-based testing into ConCert using QuickChick and our development is the first to support testing properties of interacting smart contracts. We test several complex contracts such as a DAO-like contract, an escrow contract, an implementation of a Decentralized Finance (DeFi) contract which includes a custom token standard (Tezos FA2), and more. In total, this gives us a way to write dependent programs in Coq, test them semi-automatically, verify, and then extract to functional smart contract languages, while retaining a small trusted computing base of only MetaCoq and the pretty-printers into these languages.

AB - We implement extraction of Coq programs to functional languages based on MetaCoq's certified erasure. As part of this, we implement an optimisation pass removing unused arguments. We prove the pass correct wrt. a conventional call-by-value operational semantics of functional languages. We apply this to two functional smart contract languages, Liquidity and Midlang, and to the functional language Elm. Our development is done in the context of the ConCert framework that enables smart contract verification. We contribute a verified boardroom voting smart contract featuring maximum voter privacy such that each vote is kept private except under collusion of all other parties. We also integrate property-based testing into ConCert using QuickChick and our development is the first to support testing properties of interacting smart contracts. We test several complex contracts such as a DAO-like contract, an escrow contract, an implementation of a Decentralized Finance (DeFi) contract which includes a custom token standard (Tezos FA2), and more. In total, this gives us a way to write dependent programs in Coq, test them semi-automatically, verify, and then extract to functional smart contract languages, while retaining a small trusted computing base of only MetaCoq and the pretty-printers into these languages.

KW - Blockchain

KW - Certified programming

KW - Code extraction

KW - Coq

KW - Formal verification

KW - Proof assistants

KW - Property-based testing

KW - Smart contracts

KW - Software correctness

UR - http://www.scopus.com/inward/record.url?scp=85100550870&partnerID=8YFLogxK

U2 - 10.1145/3437992.3439934

DO - 10.1145/3437992.3439934

M3 - Article in proceedings

AN - SCOPUS:85100550870

SP - 105

EP - 121

BT - CPP 2021 - Proceedings of the 10th ACM SIGPLAN International Conference on Certified Programs and Proofs, co-located with POPL 2021

A2 - Hritcu, Catalin

A2 - Popescu, Andrei

PB - Association for Computing Machinery

T2 - 10th ACM SIGPLAN International Conference on Certified Programs and Proofs, CPP 2021, co-located with POPL 2021

Y2 - 17 January 2021 through 19 January 2021

ER -