zkBitcoin: Zero-Knowledge Applications for Bitcoin

Repo: https://github.com/sigma0-xyz/zkbitcoin This video is just a quick overview of what zkBitcoin is and how you can use it as a user! Next, you can watch the walkthrough of the whitepaper: https://youtu.be/3Y-Z4nZB8FE And the walkthrough of the codebase: https://youtu.be/gSNrRPauIEA The abstract of the paper: We introduce a light multi-party computation protocol to verify zero-knowledge circuits on Bitcoin. This enables two use-cases: state-less zkapps (zero-knowledge applications) that lock funds on Bitcoin until users unlock them using zero-knowledge proofs, and stateful zkapps that allow users to update, deposit, and withdraw from a zkapp using zero-knowledge proofs. Since zero-knowledge proofs can’t be verified directly on Bitcoin (for lack of optimized opcodes) we use a multi-party committee to verify them off-chain and compute a single on-chain sig-nature. The protocol is akin to a minimal layer 2 on top of Bitcoin that uses Bitcoin as a data-availability layer. Specifically, the committee in charge of verifying zero-knowledge proofs does not have to be connected to the chain as hashes of circuits (verifier keys) are stored in UTXOs on-chain, and the latest state of a (stateful) application is also stored and kept on-chain.