What is Tornado Cash?

Tornado Cash is a privacy tool for Ethereum and compatible networks that hides which wallet sent funds to which. It is the best-known example of a crypto mixer, and it has become a test case for how far governments can go in policing open-source code and the people who write it.

How does Tornado Cash work?

Unlike a mixing company, Tornado Cash runs as smart contracts that developers first deployed on Ethereum in 2019. According to the project's documentation:

1. A user deposits a fixed amount of a token into a pool. The contract stores a cryptographic commitment, and the user keeps a secret note.
2. Later, the user withdraws to a different address by submitting a zero-knowledge proof. The proof shows they hold a valid note without revealing which deposit was theirs.
3. A published value called a nullifier stops the same note from being used twice.

A third party called a relayer can pay the gas for the withdrawal, so the new address does not need funding from a known wallet. Privacy depends on how many people use the same pool and how long funds sit before withdrawal.

What is Tornado Cash used for?

Supporters use it for ordinary financial privacy, since every Ethereum transfer is otherwise public, as explained in can cryptocurrency be traced. Criminals have used it too. The Treasury said in 2022 that it had laundered more than $7 billion since 2019, including over $455 million stolen by North Korea's Lazarus Group. Prosecutors put criminal proceeds through it at more than $1 billion, much of it from the Ronin hack.

Is Tornado Cash still sanctioned?

No, as of November 2026. The Treasury's Office of Foreign Assets Control added Tornado Cash to its sanctions list on August 8, 2022. On November 26, 2024, the Fifth Circuit ruled in Van Loon v. Department of the Treasury that its immutable smart contracts are not property under the sanctions law, because no one can own, change or control them. The ruling did not cover contracts that can be changed. On March 21, 2025, the Treasury removed the sanctions, citing novel legal and policy issues, while saying it remained deeply concerned about North Korean laundering.

What happened to Tornado Cash co-founder Roman Storm?

In August 2023, prosecutors in New York charged co-founders Roman Storm and Roman Semenov with conspiracies to commit money laundering, violate sanctions and run an unlicensed money transmitting business. Semenov remained at large.

In August 2025, a jury convicted Storm of the unlicensed money transmitting conspiracy, which carries up to five years in prison. It could not agree on the other two counts. Storm asked the judge to acquit him. As of October 7, 2026, Cointelegraph reported that Judge Katherine Polk Failla had not ruled on that motion and that a retrial on the open counts was scheduled for April 26, 2027. Prosecutors cited a September 2026 appeals ruling that upheld the conviction of the operator of another mixer, Bitcoin Fog.

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