A New Tool Aims to Thwart 3D-Printed Gun File Detection

What Hochulization Does

Cody Wilson, the founder of Defense Distributed, has released a tool he calls Hochulization. It modifies the digital hash of a 3D-printed gun file without changing the part itself. The idea is simple: if a printer's built-in detection software looks for known gun file hashes, Hochulization changes those hashes so the file no longer matches the block list. The printed suppressor or firearm still works exactly as before.

Wilson named the tool as a direct reference to New York Governor Kathy Hochul, who pushed through the nation's first law requiring new 3D printers to include gun file detection software. The law passed as part of New York's FY 2027 budget.

How Detection Software Is Supposed to Work

The current approach relies on hashing. Every 3D model file generates a unique string of characters when run through a hashing algorithm. Regulators would maintain a database of known gun file hashes. A printer equipped with detection software would scan files before printing and stop any that match.

Wilson's tool adds a series of bytes to the file, changing the hash while leaving the geometry intact. The result is a file that prints the same gun but carries a different digital fingerprint. He plans to apply Hochulization to all files on DEFCAD by default and has promised to release the tool as open source.

Why This Matters Beyond Guns

The same hash-matching logic raises questions for every open-source 3D printing community. Makers, educators, and small businesses could see non-gun files flagged incorrectly if detection models are too broad. Some in the industry worry that gun-file scanning introduces a new layer of digital surveillance into desktop fabrication.

More advanced detection systems use AI to analyze geometry rather than just matching hashes. Wilson claims his team found ways to bypass those too, including re-saving files as slightly different meshes or adding small amounts of unused geometry. He says even a custom AI detection model trained on DEFCAD files still showed a 30 percent false positive rate.

The Policy Fight Is Just Starting

New York's law is the first of its kind, but California's AB 2047 is advancing through the Senate. That bill would require new printers sold in the state to include print-blocking software starting in December 2029. Both laws leave the technical details to industry experts, which means the actual implementation is still anyone's guess.

The honest read is this: hash-based detection is easy to explain and cheap to implement, but it is also easy to defeat. Stronger AI-based detection comes with a higher risk of blocking legitimate files. Regulators, makers, and printer companies are now caught in the middle, and no one has agreed on a standard that balances safety with open design.