Proof of Quantum Solvency: the standard, the registry and the data feed

Proof of Reserves answers one question: do the coins exist. It does not answer the next one: how much of that reserve sits behind a public key that is already visible on-chain, and would therefore be the first thing a large enough quantum computer could take. Over the past week LatticeScan shipped three pieces that answer it, and make the answer something a second party can check.

The standard

[Proof of Quantum Solvency v1](/spec) is an open specification, licensed CC BY 4.0. It defines which addresses count as exposed (on Bitcoin: pay-to-public-key, Taproot as designed in BIP-341, and any address that has been reused or spent from; on Ethereum, any account that has sent a transaction), how the solvency figure is computed from balances, the practical-risk tiers, what a policy attestation is, the signed document format, and how a snapshot is anchored in Bitcoin so its date cannot be moved later.

It ships with a reference verifier: one file, no dependencies beyond Node.js, that checks the signature, the anchor and the arithmetic of any document we issue. Anyone may implement the standard, and any firm may assess against it.

The registry

The quantum threat is that a private key can one day be recovered from a public key. On that day a thief and the true owner can both sign for the same coins, and nothing on-chain says which is which. The [registry](/registry) lets an owner settle that in advance. While only they control the key, they sign a short statement with their wallet naming a post-quantum public key of their own (ML-DSA-65, the NIST FIPS 204 signature standard). We verify the signature by recovering the public key and deriving the address from it, record the statement, and stamp its hash into Bitcoin through OpenTimestamps. Nothing moves, nothing costs anything, and the result is a dated, unforgeable claim of ownership made before anyone else could make one.

It works today for Bitcoin legacy and SegWit addresses and any Ethereum account. Taproot needs the BIP-322 proof format and is next.

The feed

The [Quantum Solvency Index](/quantum-solvency) is now available as data: one versioned JSON document with every scored reserve, the market-wide number, the reserves that cannot be scored yet and why, and registry totals; a CSV; badges per reserve, for the market and per registered address; and a widget that fits in an iframe. The feed is signed and only ever adds fields within a version. Programmatic access is by API key, issued to partners; the [integration page](/integrate) explains how wallets, exchanges, custodians, funds and data platforms can plug in, and that we will do the work with them.

Where the numbers stand

From each holder's own published address set against public chain data: Binance 16.8% quantum solvent, OKX 46.9%, El Salvador's national reserve 100%. Weighted by balance, 23.0% across the 801,268 BTC scored so far. Every figure links to its signed snapshot and its Bitcoin timestamp proof.