AUTHOR=Bartoletti Massimo , Zunino Roberto 

TITLE=Formal Models of Bitcoin Contracts: A Survey

JOURNAL=Frontiers in Blockchain

VOLUME=2

YEAR=2019

URL=https://www.frontiersin.org/journals/blockchain/articles/10.3389/fbloc.2019.00008

DOI=10.3389/fbloc.2019.00008

ISSN=2624-7852

ABSTRACT=<p>Although Bitcoin is mostly used as a decentralized application to transfer cryptocurrency, over the last 10 years there have been several studies on how to exploit Bitcoin to execute <italic>smart contracts</italic>. These are computer protocols which allow users to exchange bitcoins according to complex pre-agreed rules. Some of these studies introduce formal models of Bitcoin contracts, which specify their behavior in non-ambiguous terms, in some cases providing tools to automatically verify relevant contract properties. In this paper, we survey the formal models proposed in the scientific literature, comparing their expressiveness and applicability in the wild.</p>