- Zero-knowledge proofs (ZKPs) are coming to Bitcoin to expedite the process of verifying individual blocks and the entire blockchain.
- Swiss-based nonprofit ZeroSync Association is developing open-source software that enables succinct ZKPs on the Bitcoin blockchain.
- ZeroSync Association uses StarkWare’s proprietary zero-knowledge Scalable Transparent Argument of Knowledge (zk-STARK) validity proofs to generate ZKPs for the Bitcoin network.
Zero-knowledge proofs have fueled the development of Ethereum layer 2s, and they’re now making their way to Bitcoin. Users of Bitcoin (BTC) will soon be able to use zero-knowledge proofs (ZKPs) to speed up the verification of individual blocks and, eventually, the entire blockchain.
The ZeroSync Association, based in Switzerland, is developing tooling that will allow users to validate the state of the Bitcoin network without downloading the blockchain or relying on a third party for verification.
The ZeroSync Association was founded to create and maintain open-source software that enables concise zero-knowledge proofs (ZKPs) on the Bitcoin blockchain. To generate ZKPs for the Bitcoin network, the group employs StarkWare’s proprietary zero-knowledge Scalable Transparent Argument of Knowledge (zk-STARK) validity proofs.
The tool promises to simplify the process of verifying the Bitcoin blockchain, which requires node operators to download a large amount of data to synchronize the Bitcoin network’s correct state.
ZeroSync is using ZKPs to generate valid proof to almost instantly verify the most current state of the blockchain.
ZKPs have been a revelation for the Ethereum ecosystem, with various proof methods powering several layer-2 scaling platforms such as Polygon, Arbitrum, Optimism, and StarkNet.
The ZeroSync Association’s announcement highlights ZKPs’ promise for Blockchain Scalability and Privacy by providing ‘almost-fixed-size’ proofs verifying large computations.
The project’s work pioneers the use of ZKPs for the Bitcoin network, with the organization describing Bitcoin’s relative simplicity and UTXO model as a unique value proposition for the benefit of recursive proofs.
The ZeroSync Association also points out that the ZKP tools do not necessitate any changes in consensus or additional trust assumptions for the Bitcoin network and its users. The organization is developing a software development kit (SDK) that will allow developers to generate custom validity proof for specific use cases without requiring extensive domain knowledge.
ZeroSync is developing a client for fast initial block download (IBD) and implementing the first complete proof of Bitcoin consensus. The client will allow users to sync a full node without modifying the Bitcoin Core code.
To create STARK-provable computation programs, ZeroSync employs the Cairo programming language pioneered by StarkWare.
ZeroSync’s tool is still in the prototype stage, but it can prove the validity of individual assumed valid blocks, which validate all Bitcoin rules except Scripts. The team also has an operational in-browser demo verifier for STARK proofs of Bitcoin blocks.
The ZeroSync Association was financed mainly by Geometry and StarkWare but is now establishing a nonprofit entity to allow ongoing development and maintenance from Bitcoin community stakeholders.
StarkWare president and co-founder Eli Ben-Sasson, who co-invented zk-STARKS, summarized the significance of ZKPs entering the Bitcoin ecosystem:
“After years of frustration about slow syncing, users will be able to sync with the network much faster and with less computation. It is a technological leap akin to the transition from slow dial-up internet to high-speed broadband.”
Lightning Labs, the team behind Bitcoin layer-2 Lightning Network payment system, is a contributing partner to ZeroSync’s project.
The company plans to use ZeroSync to power compressed transaction history proofs for its Taproot Asset Representation Overlay (Taro) protocol, which aims to power digital asset issuance on the Bitcoin blockchain.
