Tornado Cash to Use Chainalysis to Block OFAC Sanctioned Addresses

  • Roman Semenov, co-founder of Tornado Cash, explained that the blockade only applies to the platform’s frontend, and not the underlying smart contract.
  • The news came only a day after the Treasury Department alleged that North Korean hacker group Lazarus was connected to the $625 million Ronin bridge hack.
tornado cash


Popular token mixer Tornado Cash will now be using a Chainalysis tool to block crypto addresses sanctioned by the U.S. Office of Foreign Asset Control (OFAC), the platform said on Twitter on 15 April.

According to the announcement, through the use of Chainalysis’ oracle contract Tornado Cash — one of the most popular Ethereum mixers, which is often used to obfuscate crypto transactions connected to hacks — will be able to block OFAC sanctioned addresses from accessing its Ethereum mixer. The platform tweeted:

Roman Semenov, co-founder of Tornado Cash, later explained that the change applies only to its frontend — the user-facing decentralized application (dApp) — and not the platform’s underlying smart contract. Back in March, Semenov told Bloomberg that it was “technically impossible” to enforce sanctions on decentralized protocols as “smart contracts are immutable”.

The news came only a day after the Treasury Department alleged that North Korean hacker group Lazarus was connected to the exploit of Axie Infinity’s Ronin bridge, which saw $625 million being stolen from the platform. Blockchain analysis firm Elliptic noted on Thursday that almost $81 million from the Ronin hack has already gone through Tornado Cash.

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