# Bitcoin Cash (BCH) Quantum Readiness Report

> Bitcoin Cash has a QRI score of 40.88/100 and is assessed at Stage 3 (Migration Live) with medium evidence confidence.

Evaluation date: 2026-06-01. Review status: draft. Evaluated scope: Native asset (BCH) on Bitcoin Cash PoW UTXO chain.

Bitcoin Cash (BCH) is a PoW UTXO chain that activated the 'Layla' / CashVM upgrade on May 15, 2026, introducing VM primitives (Loops, Functions, Bitwise, P2S) that enable efficient opt-in post-quantum vaults via Quantumroot. Quantumroot uses LM-OTS (RFC 8554, NIST SP 800-208) based on SHA-256, providing 256-bit classical and 128-bit quantum security. It was tested on Chipnet from November 2025 and is now live on mainnet. However, default spend authorization remains entirely ECDSA/Schnorr (secp256k1), and nearly all BCH value is held in classical addresses. Legacy P2PK outputs with exposed public keys and reused P2PKH addresses represent material long-exposure quantum-vulnerable value with no active migration, freeze, or enforced recovery mechanism. The challenge-based transition protocol proposed on Bitcoin Cash Research (April 2026) is a research design, not an active policy. Quantumroot has no independent audit. QRI Score of 41 reflects Stage 3 (Migration Live) with an opt-in PQ path available but default vulnerability, negligible migration coverage, and long-exposure vulnerable value capping readiness.

## Core resources

- [Bitcoin Cash QRI report](https://qrindex.org/projects/bitcoin-cash/): Human-readable assessment with score, stage, evidence, blockers, risks, and assurance notes.
- [Bitcoin Cash structured report data](https://qrindex.org/projects/bitcoin-cash/report.json): Complete report as JSON for deterministic machine processing.
- [QRI methodology](https://qrindex.org/methodology/): Scoring model, evidence handling, readiness stages, confidence, assurance, and report status.
- [All QRI project reports](https://qrindex.org/llms.txt): Score-ranked index of every published project assessment.
- [Bitcoin Cash official website](https://bitcoincash.org): Project-maintained website.
- [Bitcoin Cash source repository 1](https://gitlab.com/bitcoin-cash-node/bitcoin-cash-node): Project source code referenced by QRI.
- [Bitcoin Cash source repository 2](https://github.com/bitcoin-cash-node/bitcoin-cash-node): Project source code referenced by QRI.



## Evidence sources

- [Evidence source 1](<https://bitcoincashresearch.org/t/quantum-resistant-bitcoin-cash-a-challenge-based-transition-protocol>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 2](<https://bitjson.com/quantumroot>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 3](<https://github.com/bitjson/quantumroot>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 4](<https://blog.bitjson.com/quantumroot-on-chipnet/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 5](<https://upgradespecs.bitcoincashnode.org/transaction/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 6](<https://reference.cash/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 7](<https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/2019-05-15-schnorr.md>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 8](<https://blog.bitjson.com/quantumroot/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 9](<https://thequantuminsider.com/2026/05/26/bitcoin-quantumroot-vaults-go-live-on-cashvm-upgrade-unlocks-turing-complete-defi-on-l1-with-cashtokens/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 10](<https://upgradespecs.bitcoincashnode.org/2026-05-15-upgrade/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 11](<https://bitcoincash.org/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 12](<https://github.com/OPTNLabs/OPTNWallet>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 13](<https://www.paytaca.com/>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 14](<https://buyhodlsell.com/articles/bch-quantum-resistance>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 15](<https://bitinfocharts.com/bitcoin%20cash-distribution-history.html>): Public source cited by the Bitcoin Cash QRI assessment.
- [Evidence source 16](<https://www.rfc-editor.org/rfc/rfc8554>): Public source cited by the Bitcoin Cash QRI assessment.