The Ethereum community’s push for privacy comes amid ongoing scrutiny of privacy-preserving blockchain tools by regulators. While Railgun aims to enable legitimate private transactions, similar tools have drawn legal fire.
Tornado Cash—once the most widely used Ethereum-based mixer—was sanctioned by the U.S. Department of the Treasury’s Office of Foreign Assets Control (OFAC) in August 2022. The government alleged the platform was used to launder over $1 billion, including funds linked to North Korea’s Lazarus hacking group.
However, on March 21, 2025, OFAC officially lifted the sanctions against Tornado Cash following a federal appeals court ruling that the agency had overstepped its authority.
Railgun, described on its website as a “DeFi privacy toolkit,” represents a newer generation of privacy systems built on Ethereum, combining zero-knowledge cryptography with smart contract composability. This newer system, unlike Tornado Cash, incorporates screening features to deter illegal transactions.
Notably, in February, Buterin commended Railgun for its successful prevention of a money-laundering attempt.
Also unlike Tornado Cash, which is primarily built to help users transfer funds anonymously, Railgun helps users interact directly with DeFi protocols — allowing investors to transact discretely while maintaining full control of their funds.
The project has received support from some privacy advocates and developers, who argue that tools like Railgun can serve legal use cases such as financial privacy for activists, journalists, or high-net-worth crypto “whales” who want to transact with discretion.