The Swiss-based nonprofit ZeroSync Association is developing a tool that will allow Bitcoin users to validate the state of the network using zero-knowledge proofs (ZK-proofs) without having to download the entire blockchain or trust a third party.To generate ZK-proofs for the Bitcoin network, ZeroSync is utilizing StarkWare’s exclusive Zero-Knowledge Scalable Transparent Argument of Knowledge (zk-STARK) validity proofs. The goal is to overhaul the process of verifying the Bitcoin blockchain, which currently requires node operators to download large amounts of data to synchronize the correct state of the network. ZeroSync’s ZK-proofs will allow for almost-instantaneous verification of the latest state of the blockchain.
This application of ZK-proofs is a first for the Bitcoin network, although various proof methods have been powering scaling platforms in the Ethereum ecosystem. The project’s work pioneers the use of ZK-proofs for the Bitcoin network’s scalability and privacy, without requiring consensus changes or additional trust assumptions for the network and its users. At present, ZeroSync is constructing a client that enables a quick initial block download and executing the initial comprehensive proof of Bitcoin consensus. While the tool is currently in a prototype stage, it can verify the authenticity of assumed valid individual blocks, and the team has developed a working in-browser demo verifier for STARK proofs of Bitcoin blocks. Initially funded by Geometry and StarkWare, the ZeroSync Association is forming a non-profit organization to facilitate continuous development and upkeep from stakeholders in the Bitcoin community.
Lightning Labs, the team behind the Bitcoin layer-2 Lightning Network payment system, is a contributing partner to ZeroSync’s project, intending to use it to power compressed transaction history proofs for its Taproot Asset Representation Overlay (Taro) protocol, which aims to power the issuance of digital assets on the Bitcoin blockchain.
