Proof Systems
Introducing a game-changing compression technique.
Succinct zero-knowledge proofs (zkSNARKs) promise a paradigm shift in blockchain scalability and privacy. While considerable engineering effort is underway in the Ethereum community to apply this technology, no similar investment has yet been made for the Bitcoin network. Therefore, ZeroSync was created to bring these proof systems to Bitcoin for the first time.
ZeroSync's Mission
Pioneering the Adoption of Proof Systems in the Bitcoin Ecosystem.
At ZeroSync, our mission is to catalyze the use of proof systems in the Bitcoin ecosystem to improve scalability, accessibility, and privacy. Our main activities are:
- Creating a proof system to sync Bitcoin's chain state instantly. Additionally, a toolkit for developers to enhance existing protocols, applications, and services with ZKPs.
- Building a community around Bitcoin proofs by presenting the tech at conferences, by providing resources to get people engaged, and by collaborating with other projects in the space.
- Working towards the eventual integration of a ZKP verifier into the main layer of Bitcoin.
Projects
ZeroSync is spearheading numerous applications of proof systems to Bitcoin
Our main projects are chain state proofs, BitVM, and zkCoins.
Chain State Proofs - Instantly sync a node
Similar to an SPV light client, the headers state proof verifies only the block headers, the proof of work, and the difficulty adjustments. Additionally, it augments the header chain with a Merkle tree over all block headers, which enables succinct proofs of inclusion for all blocks and transactions.
We have broadcasted state proofs from space via the Blockstream Satellite, for everyone to instantly sync the Bitcoin blockchain almost anywhere on earth.
BitVM: Compute anything on Bitcoin
BitVM is a computing paradigm to enable arbitrary computation on Bitcoin. Most notably, it allows to bridge BTC to second layers, enabling trust-minimized second layers such as sidechains, rollups, and zkCoins.
zkCoins: Improving Bitcoin scalability and privacy
The zkCoins protocol combines client-side validation with zero-knowledge proofs, increasing Bitcoin's throughput to more than a hundred transactions per second while offering strong privacy.
Research
ZeroSync is at the forefront of Bitcoin research and innovation
We are involved in a range of research projects, involving applied cryptography, cryptoeconomics, and advanced Bitcoin Script.
- ZeroSync: Introducing Validity Proofs to Bitcoin.
- BitVM: Compute Anything on Bitcoin. A computing paradigm to express Turing-complete Bitcoin contracts.
- BitStream: Decentralized File Hosting Incentivized via Bitcoin Payments.
- BitVM2: Bridging Bitcoin to Second Layers. A collaboration with professor Matteo Maffei and his Security and Privacy group at TU Vienna.
- Remote Staking with Optimal Economic Safety. The first bitcoin-backed proof of stake algorithm, developed in collaboration with professor David Tse and his group at Stanford University.
- ShieldedCSV: Private and Efficient Client-Side Validation. A payment system with strong privacy and scalability, combining a client-side validation protocol with validity proofs. A collaboration with Liam Eagen and Jonas Nick from Blockstream Research.
- Push-Button Verification for BitVM Implementations.
- BitVM: Quasi-Turing Complete Computation on Bitcoin.
- Dark Skippy: A novel mechanism for key exfiltration attacks. Co-created with Lloyd Fournier and Nick Farrow.
“After years of frustration about slow syncing, users will be able to sync with the network much faster, and with less computation. It’s a technological leap akin to the transition from slow dial-up internet to high-speed broadband”

“ZeroSync is first of its kind in the Bitcoin space, compressing the chain and producing proofs about processing its state in a light client manner today and as a full node in the future, enabling new ways to interact with Bitcoin. It’s an ambitious project which is led by a motivated and smart team that I had the luck to see take it from an idea that seemed extremely hard to a reality.”

“ZeroSync is an amazing project tackling this design space.”

About
We are a Swiss nonprofit organization developing public goods.
Purpose
The ZeroSync Association is a nonprofit organization based in the Swiss canton of Zug. Its purpose is to spearhead the application of proof systems to Bitcoin both in terms of research and open-source software development.
Core Contributors
Robin Linus, Lukas George, Tino Steffens, Max Gillett, Andrew Milson
Sponsors
ZeroSync development is sponsored by research grants from
Media
Learn more about STARKs on Bitcoin
Publications and Articles
A selection of publications and articles about the technology and the project.
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Research paper
ZeroSync: Introducing Validity Proofs to Bitcoin
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Geometry Notebook:
Introduction to ZeroSync
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ZeroSync and Blockstream to Broadcast Bitcoin Zero-Knowledge Proofs From Space
- CoinDesk -
Zero-knowledge proofs coming to Bitcoin, overhauling network state validation
- CoinTelegraph -
Tested on Ethereum, StarkWare’s Zero-Knowledge Proofs Are Now Live on Bitcoin
- Decrypt -
Bitcoin Nodes Now One Step Closer To Instant Sync
- Bitcoin Magazine -
Bitcoin’s first zero-knowledge light client seeks to drive innovation
- Blockworks -
ZeroSync implements first Stark-based ZK client for Bitcoin
- The Block
Presentations and Podcasts
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Newly Formed ZeroSync Association Brings Zero-Knowledge Proofs to Bitcoin
- Interview with CoinDesk -
Andrew Milson’s talk on
Provers for Consumers
at StarkWare Sessions 2023, Tel Aviv -
Olaoluwa Osuntokun's talk on
STARKs on Bitcoin: From Outside In
at StarkWare Sessions 2023, Tel Aviv -
Lukas George and Robin Linus on Blockstream Talk
ZeroSync & Blockstream Satellite
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Presentation
Zero-Knowledge Proofs for Bitcoin
at MIT Bitcoin Expo 2023, Cambridge MA -
Presentation
Building a Zero Knowledge Proof System for Bitcoin
s at Bitcoin Builders 2023, Miami -
Robin Linus' presentation
Introducing Validity Proofs to Bitcoin
at Bitcoin 2023, Miami - Lukas George and Robin Linus on the Bitcoin Optech Recap about our research paper
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Stephan Livera Podcast
ZeroSync: Speeding up Bitcoin IBD
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Robin Linus on the Bitcoin Optech Recap about the
Some Day Peg
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Presentation
Bitcoin STARKs
at StarknetCC 2023, Paris -
Online presentation
zkCoins: A novel token protocol with strong privacy and scalability
at BTC Startup Lab -
Can the Bitcoin Blockchain be compressed from 600GB down to a few MBs?
Interview with Bitcoin News - Robin Linus at MIT Bitcoin Expo: BitVM
History
Growing from an idea into reality.
- In February 2022, Lukas George started STARK relay, his bachelor's thesis at Technical University of Berlin, in which he implemented and benchmarked a first basic proof of Bitcoin's header chain.
- Geometry offered a research grant to fund the initial development.
- In July 2022, Robin Linus joined as project lead and together they founded ZeroSync to implement a full state proof.
- Ruben Somsen gave the project its name ZeroSync.
- In September 2022, Max Gillett, who developed the Giza prover, joined the team to help implement a STARK verifier in Cairo for proof recursion.
- In February 2023, they completed their first major milestone, a basic prototype of a recursive state proof that verifies all Bitcoin consensus rules except for the witness data.
- In March 2023, Giacomo Zucco, who co-authored the RGB protocol with Peter Todd, helped them found the ZeroSync Association in Switzerland to grow now into a long-term project.
- In April 2023, Robin Linus published the zkCoins writeup, combining client-sided validation with zero-knowledge proofs.
- In June 2023, Andrew Milson, who developed the miniSTARK prover, joined the team to help optimize the prover performance and complete a production-ready chain proof.
- In September 2023, the team completed a header chain proof, enabling Bitcoin's first zk-client.
- In October 2023, Robin Linus published the BitVM white paper, introducing a novel mechanism for arbitrary computation on Bitcoin.
- In March 2024, ZeroSync completed a first prototype of BitVM.
- In April 2024, Robin Linus published the BitVM bridges white paper, introducing the first trust-minimized Bitcoin bridge.
- In September 2024, ZeroSync founded the BitVM Alliance, joining forces with a number of Bitcoin L2 companies to implement BitVM bridges.
- In September 2024, Robin Linus published Shielded CSV together with Jonas Nick and Liam Eagen from Blockstream research.
- In March 2025, ZeroSync completed a first proof-of-concept implementation of zkCoins.
- In March 2025, the BitVM Alliance completed the first implementation of BitVM bridges.