A Zero-Knowledge Proof Is Verified on Bitcoin For The First Time in History

Weikeng Chen, with sponsorship from Starkware, has produced the first implementation of a zero-knowledge verifier using Bitcoin script, which was confirmed on Bitcoin's Signet testnet on July 12, 2024. The project, called the "Bitcoin Wildlife Sanctuary," builds a STARK verifier using the OP_CAT opcode, with the STARK proof based on Starkware's open-source Stwo implementation and split into chained transactions. Chen says the proof of concept is not production-ready and that validity proofs take a lot of block space, which could become expensive.