hazync

Sync Bitcoin from a proof, not from trust.

Hazync proves Bitcoin's history using Bitcoin Core's own consensus code, run inside a zero-knowledge VM. The goal is one proof of the whole chain that any node can check in milliseconds, so verifying Bitcoin never gets harder as the chain grows.

Now on Hazync v2. The board restarted on the new engine on 12 November 2026 and is proving the chain again from genesis. What changed.

Reading progress from the proof party board…

  • Anchored
  • Proven
  • Not yet proven
Explore proven blocks Verify a proof yourself

Hazync v2

A new engine, libzync, released as v0.24.0.

Achieved

What already works, newest first. Entries before November 2026 were on Hazync v1.

  1. 12 November 2026

    Hazync v2 and the first zAPPs

    The libzync engine ships as v0.24.0 on RISC Zero 3.1.0, the public board restarts on it, and its first proving run proves 1,287 blocks in under three hours. The zAPPs.

  2. 10 November 2026

    Every Bitcoin header in one proof

    All 975,279 headers from genesis, proved valid under Core's header rules in under an hour on one GPU. Check it yourself.

  3. 9 November 2026

    Proving on Windows

    A Windows PC with an NVIDIA card proves blocks natively, with no Linux layer, and the proofs check out on Linux.

  4. 29 September 2026

    Follow the tip for an hour

    Every block Bitcoin produced in an hour was proven as it was mined, each one finished before the next arrived, forming an unbroken chain from 969,118 to 969,122. The full record.

  5. 26 September 2026

    Block sponsorship, paid in bitcoin

    Pay for a block's proof and your name goes on it. The first sponsorship was paid over Lightning; a bot rented a card, proved block 196,001 and released it. Donations are open.

  6. 10 September 2026

    A near-tip block in under 10 minutes

    Block 966,256, with 9,079 inputs, proven in 544.0 seconds on 27 rented RTX 4090s.

  7. 5 August 2026

    Sync a node from a proof

    A Bitcoin node on mainnet loaded a proven set of unspent coins and carried on from the proven height, without re-checking the blocks below it. Shown at low height, not yet at scale.

  8. 1 August 2026

    Verify on small hardware

    A WebAssembly verifier checks a proof in a browser in tens of milliseconds, using under 2 MiB of memory. Try it.

  9. 25 July 2026

    Every era of Bitcoin

    Real blocks from each era validated: early coinbases, SegWit, Taproot and the largest blocks.

  10. July 2026

    A reproducible build

    Builds of the prover on different machines produce the same program ID, bit for bit, so a proof can be tied to published source.

  11. July 2026

    The proof party protocol

    An open board where anyone proves any block and signs it with their own key. The coordinator re-checks every proof before it counts, and anyone can download and check them again.

  12. July 2026

    Bitcoin Core's consensus code, proven in a zkVM

    Core's script interpreter, signature hashing and libsecp256k1, compiled to RISC-V and proven as they are, not rewritten.

Targets

The path from here to a proven chain.

  1. Prove the whole chain on v2

    Now

    The board is proving upwards from genesis on the new engine, block by block, and anyone with an NVIDIA GPU can join. Contribute.

  2. Follow the tip on v2

    Next

    Prove each new block as it is mined, as v1 did for an hour in September, so the proof never falls behind.

  3. Independent audit and reproduction

    Planned

    A commissioned audit, starting with Hazync's own code: the coin log, the counting trie and the batch signature check. Builders outside the project reproducing the program ID from source.

  4. More zAPPs

    Planned

    New apps on the same record of coins. Coin check already reads the board's latest proof, brought up to date every ten minutes.

  5. Sync a node at scale

    Planned

    Sync bitcoind from a proof at a height with real transaction volume, and measure how much faster it is than checking the blocks itself.

  6. Tooling for partners

    Planned

    Proof distribution, verifier libraries for nodes and wallets, and integrations for projects that need proven Bitcoin state.