A large-scale empirical study of low-level function use in Ethereum smart contracts and automated replacement

Researcher(s)

Rui Xi, Karthik Pattabiraman

Date of Publication

Description

The Ethereum blockchain stores and executes complex logic via smart contracts written in Solidity, a high-level programming language. The Solidity language (in its early versions) provides features to exercise fine-grained control over smart contracts, whose usage is discouraged by later-released Solidity documentation, but nonetheless supported in later versions for backward compatibility. We define these features as low-level functions. However, the high-volume of transactions and the improper use of low-level functions lead to security exploits with heavy financial loss. Consequently, the documentation suggests secure alternatives to the use of low-level functions. In this article, we first perform an empirical study on the use of low-level functions in Ethereum smart contracts. We study a smart contract dataset consisting of over 2,100,000 real-world smart contracts. We find that low-level functions are widely used and that the majority of these uses are gratuitous. We then propose GoHigh, a source-to-source transformation tool to eliminate low-level function-related vulnerabilities, by replacing low-level functions with secure alternatives. Our experimental evaluation on the dataset shows that GoHigh successfully replaces all low-level functions with 4.9% fewer compiler warnings. Further, no unintended side-effects are introduced in 80% of the contracts, and the remaining 20% are not verifiable due to their external dependency. GoHigh saves more than 5% of the gas cost of the contract. Finally, GoHigh takes 7 s on average per contract.

External Link

Read the Research Paper


  • Journal Article

First Nations land acknowledegement

We acknowledge that the UBC Point Grey campus is situated on the traditional, ancestral, and unceded territory of the xʷməθkʷəy̓əm.


UBC Crest The official logo of the University of British Columbia. Urgent Message An exclamation mark in a speech bubble. Caret An arrowhead indicating direction. Arrow An arrow indicating direction. Arrow in Circle An arrow indicating direction. Arrow in Circle An arrow indicating direction. Chats Two speech clouds. Facebook The logo for the Facebook social media service. Information The letter 'i' in a circle. Instagram The logo for the Instagram social media service. External Link An arrow entering a square. Linkedin The logo for the LinkedIn social media service. Location Pin A map location pin. Mail An envelope. Menu Three horizontal lines indicating a menu. Minus A minus sign. Telephone An antique telephone. Plus A plus symbol indicating more or the ability to add. Search A magnifying glass. Twitter The logo for the Twitter social media service. Youtube The logo for the YouTube video sharing service.