Controversial mixer Tornado Cash open-sources UI code

The decentralized solution has grown in popularity over the past two years as more cryptocurrency users have sought privacy-preserving protocols.

Cryptocurrency mixer Tornado Cash has fully open-sourced its user interface (UI) code — a move its developers say fulfills their mandate of complete decentralization and transparency. 

Tornado Cash Classic UI became fully open-sourced on Thursday, the protocol’s anonymous developers announced in a Medium blog post. Although the protocol’s UI has been decentralized since 2020, its open sourcing means anyone can analyze Tornado Cash’s UI pools and make pull requests to improve the project. In the software development world, a pull request is when a developer is ready to merge new code changes with the project's main repository.

Technically, Tornado Cash’s open-sourcing allows anyone to fork the repository and modify the code as they see fit.

“We personally grew fond of the black & green floating astronaut associated with the protocol," the developers said, referring to the current website interface. “However, you should know our credo by now: We will always lean towards more decentralization. As far as we are concerned, our DAO took a step further with this great progress.”

A DAO, or decentralized autonomous organization, is an internet-native organization collectively managed by its members with no central authority or leadership. Tornado Cash first announced its DAO in mid-2020.

Tornado Cash currently has over $300 million in total value locked, or TVL, according to DeFi Llama. This figure was closer to $850 million in November 2021 when the project announced the launch of its layer-2 scaling network on Arbitrum.

Related: Crypto privacy is in greater jeopardy than ever before — Here's why

The Tornado Cash protocol has been at the center of several decentralized finance exploits, including the $375 million wormhole attack in February and the more recent $100 million Horizon Bridge hack. Currently, the protocol supports mixing a maximum of 100 Ether (ETH) at a time.

Tornado Cash was also used following the $600 million hack of Axie Infinity's Ronin software bridge in March. According to VICE, the hackers were successful in sending a portion of the proceeds, roughly $100 million at the time, to the protocol. As Bloomberg later reported, roughly 2,000 ETH lifted from the software bridge was moved to the protocol in batches of 100 ETH beginning in early April. 

15% of Tornado deposits are from the Ronin exploiter pic.twitter.com/yYsisOzJvu

— Alex Svanevik (@ASvanevik) April 30, 2022

However, the Tornado Cash community and developers have cautioned people not to automatically associate the protocol with malicious behavior as virtually any digital tool can be used with unlawful intent. The protocol has been designed to hand over ownership of privacy to cryptocurrency users so that they can decide when and with whom to share their information. According to the Tornado Cash website, the protocol has a compliance tool that allows users to prove the source of their funds.

"Unfortunately, some news & stories come to tarnish the image of privacy tools such as Tornado Cash," community members elected by the protocol's DAO wrote in a Medium post earlier this year, adding:

"Community members of Tornado Cash DO NOT support such unlawful usage of the tool. It stands miles away from the values conveyed by the DAO. You cannot imagine how infuriating it is to notice that a few people can call into question both Tornado Cash’s reputation & our own usage of the protocol."

This article has been updated to include comments from Tornado Cash's team.