A federal appeals court overturned key parts of the conviction against one of the principal developers behind the Tornado Cash mixing protocol on Tuesday, ruling that the government's theory of federal money-transmission liability swept too broadly and could not be sustained against contributors to immutable open-source smart-contract code. The ruling does not vacate all charges but materially narrows the precedent and is widely read as the most consequential single court decision for the legal status of crypto open-source development in years.
The underlying prosecution had become a focal point of crypto-industry constitutional concern. The original 2023 indictment alleged that the defendant, a co-founder and core developer of the Tornado Cash protocol, had operated as an unlicensed money transmitter by writing and deploying smart contracts that subsequently were used to obfuscate the origin of cryptocurrency transactions. The indictment also included separate charges for sanctions violations and conspiracy. After a multi-week trial in 2024, the defendant was convicted on all counts and sentenced to five years and four months in federal prison.
The appeals court's ruling addresses the money-transmission theory directly. The opinion holds that operating an unlicensed money-transmitting business under 18 U.S.C. § 1960 requires the alleged transmitter to have actual control over the funds being transmitted — control that the panel found absent in the case of immutable smart-contract code that no party can modify or block once deployed. The opinion preserves the sanctions-violation conviction on a different evidentiary basis but vacates the money-transmission count and remands for resentencing. The practical effect is to remove the dominant component of the original sentence and the legal foundation for the broader theory.
Reaction from the defense bar and the open-source software community was sharply positive. Coin Center, the Electronic Frontier Foundation, and Paradigm — all of which had filed amicus briefs in the appeal — issued statements describing the ruling as "a structural correction to a prosecution theory that threatened the legal status of open-source contribution to permissionless protocols." The Department of Justice did not immediately announce whether it would seek further appeal, either through a request for en banc rehearing by the full circuit or through a petition for Supreme Court review. People familiar with internal DOJ deliberations describe both options as under active consideration.
The broader implication is meaningful and operational. The original conviction had had a measurable chilling effect on open-source crypto development inside the United States: several developers of protocols with privacy or mixing features had publicly relocated, reduced their U.S. activities, or restructured their contribution patterns to limit U.S. legal exposure. The narrowed precedent does not foreclose future prosecutions of open-source contributors entirely — most importantly, the sanctions-violation theory survives — but it removes the most expansive element of the prosecution's original framework and reestablishes a meaningful zone of legal certainty around contribution to immutable, permissionless smart-contract systems.
The next milestone is the DOJ's decision on further appeal, expected within the next sixty days. If the department declines to pursue en banc or Supreme Court review, the appeals court ruling becomes the controlling precedent for the relevant circuit and the dominant persuasive authority for similar prosecutions in other circuits. If the department does pursue further review, the legal uncertainty extends potentially through 2026 or beyond. Either way, the open-source crypto-development community now operates under a meaningfully narrower theory of federal money-transmission liability than was assumed during the previous administration's enforcement era.