A Hazync developer reported on August 15 that a 1.7 MB standalone verifier validated a 226,434‑byte cryptographic receipt covering the first 1,789 Bitcoin blocks in 27 milliseconds. The result applies only to the early portion of Bitcoin’s history; a complete proof from genesis to the present tip remains unfinished.

Hazync is a research prototype that uses RISC Zero’s zero‑knowledge virtual machine (zkVM) to execute Bitcoin validation rules and produce a compact receipt that other users can verify. Proof generation concentrates on provers, while verification is performed by a larger population of participants, making the proving process computationally intensive and verification efficient. The developer estimates roughly 17 GPU‑years of compute to backfill the chain from genesis, followed by capacity equivalent to about six Nvidia L40S GPUs to keep pace with new blocks.

The project’s public repository includes a guest program compiled from parts of Bitcoin Core v28 consensus code and libsecp256k1 for 32‑bit RISC‑V, reducing the amount of consensus behavior that must be restated in a circuit. A benchmark on block 741,000, which contained 670 inputs and 394 UTXO leaves, required 55 minutes of proving across two L40S GPUs, including 27 minutes for aggregation. Available measurements represent representative project benchmarks rather than audited data across all Bitcoin eras, so the full‑chain performance estimate remains pending. The receipt’s METHOD_ID fingerprint ties each receipt to a specific guest build, and a later soundness fix could trigger a reset of the compute budget. Public code enables external review, but a commissioned professional audit is still pending.

The estimate of 17 GPU‑years for a full backfill and the need for ongoing GPU capacity to validate new blocks highlight the computational effort required before instant validation can be achieved across the entire chain.