Researchers Reupload Sanctioned Tornado Cash Code on GitHub

The US Office of Foreign Assets Control (OFAC)’s placement of popular crypto tumbler Tornado Cash as an entity on the Specially Designated Nationals (SDN) sanction list has raised many eyebrows.

The subsequent removal of its source code from the Microsoft-owned GitHub, which also shut down the user accounts of three individuals who contributed code to the project, prompted an outcry from privacy and free speech advocates.

While forks of the open source software have remained on GitHub, Matthew Green, a cryptography professor at Johns Hopkins University, this week published another fork of the software with the support of the Electronic Frontier Foundation (EFF).

Green and his EFF colleague Kurt Opsahl were not happy with the removal of Tornado Cash’s source code from Github and had argued that the hosting service had suppressed speech with the move.

Code is Speech

The main reason behind the re-uploading of the code is to test whether its removal is ever the appropriate response to sanctions. Opsahl, who happens to be EFF’s general counsel, argued that “improvements and other contributions to this fork, or any other, are protected speech, and their publication cannot be constitutionally prohibited by the government under either standard of scrutiny.”

Green also expressed a similar sentiment and revealed that if GitHub disables it again, the advocacy organization plans to challenge that decision in court. In an explanatory note, the researcher wrote,

“In my work as a researcher and instructor at Johns Hopkins, I’ve made extensive use of the Tornado Cash and Tornado Nova source code to teach concepts related to cryptocurrency privacy and zero-knowledge technology.

OFAC’s Order Ambiguous

The bone of contention is the lack of clarity of OFAC’s order as it defines “Tornado Cash” as not just a technology but also a sanctioned entity. The EFF argues that the name “Tornado Cash” in itself refers to different things, thereby creating ambiguity in what exactly is sanctioned.

It is an underlying open-source project that developed and published the code on GitHub. It is also the name of this coin mixing software that persists as a smart contract on the Ethereum network, etc. The scope of what OFAC means by “Tornado Cash” still hangs in limbo, and hence, the EFF has reached out to the Treasury Department but is yet to receive any clarity.

Meanwhile, the non-profit crypto policy think-tank Coin Center is also considering legal action against OFAC.