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 seconds, so verifying Bitcoin never gets harder as the chain grows.

Reading progress from the proof party board…

  • Proven and joined to genesis
  • Proven, not yet joined
  • Being proven now
  • Not yet proven
Explore proven blocks Verify a proof yourself

Achieved

What already works, and when it was first shown.

  1. 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.

  2. 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.

  3. 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.

  4. 25 July 2026

    Every era of Bitcoin

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

  5. 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.

  6. 5 August 2026

    Validate hazed blocks against a proof

    A ghostd node holding only stripped blocks, with every signature deleted, showed its first 1,000 blocks were the real chain, and a 3,441-byte proof showed every transaction in them was valid.

  7. 5 August 2026

    Sync a node from a proof

    A ghostd 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. 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.

    Measured, run 4. The time comes from logs and telemetry, so it is attested rather than proved. How it was measured.

Targets

The path from here to a proven chain.

  1. Follow the tip for a day

    Next

    Prove 144 consecutive blocks, a day of Bitcoin, as they are mined, and join them into one proof within 24 hours.

  2. Independent audit and reproduction

    Planned

    A commissioned audit, starting with the accumulator, the one component that is not Bitcoin Core's code. Builders outside the project reproducing the prover program ID from source.

  3. Set an anchor and start the tip cluster

    Planned

    When funding is in place, choose a checkpoint near the tip and run a dedicated cluster that proves every new block from it.

  4. Sync a node at scale

    Planned

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

  5. Backfill history

    Planned

    Whenever the tip cluster is idle between blocks, it proves the block just below the anchor, folds it in, and moves the anchor down by one. The proof party works upwards from genesis. When the two meet, the whole chain is proven from genesis and there is no checkpoint left to trust.

  6. Tooling for partners

    Planned

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