Zero-knowledge (ZK) Tax

Alex Berke

zkTax is a zero-knowledge tax disclosure system that allows individuals to make provable claims about select information in their tax returns without revealing additional information, which can be independently verified by third parties. 

The system consists of three distinct services that can be distributed: 

1. A Trusted Tax Service provides tax documents signed with a public key

2. A Redact & Prove Service enables users to produce a redacted version of the tax documents with a zero-knowledge proof attesting the provenance of the redacted data

3. A Verify Service enables anyone to verify the proof. 

We implemented a prototype with a user interface, compatible with U.S. tax forms, to demonstrate how this design could be implemented with minimal changes to existing tax infrastructure. 


Our system is designed to be extensible to other contexts and jurisdictions. zkTax provides a practical example of how distributed tools leveraging cryptography can enhance existing government or financial infrastructures, providing immediate transparency alongside privacy without system overhauls.

See our related paper for more details about the implementation.