> ## Documentation Index
> Fetch the complete documentation index at: https://docs.algovoi.co.uk/llms.txt
> Use this file to discover all available pages before exploring further.
# Zero knowledge compliance proofs
> Prove a payment was screened and compliant, and that the payer's risk score cleared a threshold, without revealing PII or the score. Commercial OEM SDK.
## What it is
**Proofs** lets you share *that* a payment was screened and compliant — and that the payer's risk
score cleared your threshold — **without revealing who the payer is or what they scored**. A
partner, counterparty, or regulator verifies the proof independently and learns the compliance
decision, and nothing else.
Most compliance tooling produces a signed claim that still carries the underlying data — which is
both a disclosure problem and a liability. Proofs does the opposite: the payer reference is a
content-addressed hash (never the cleartext), and the score sits behind a **zero-knowledge range
proof**. The verifier confirms the decision was real; the data never leaves your side.
It is **self-contained and post-quantum signed**: the compliance binding and proof envelope are
bundled, the issuer signs with Falcon-1024, and you inject a range-proof service URL and your
signing key. Verification needs only the proof and the issuer's public key — no database, no shared
infrastructure, no callback.
A Bulletproofs range proof attests that the payer's score is above your threshold while keeping
the score itself hidden. Prove the bar was cleared, reveal nothing more.
The payer reference is a `sha256` of the network and address — never the cleartext. A proof
carries the compliance decision and the payment facts, and no personal data.
One post-quantum-signed envelope binds both the screen verdict and the score-threshold proof,
so a single artifact attests the whole compliance decision.
Verify with only the proof and the issuer public key. Hand a partner the public key and they
self-serve — no service to call, no data to exchange.
## What you get
* **Compliance you can share without exposing data.** Show a regulator or partner *that* a payer
cleared screening and scored above your bar — not who they are or what they scored. The right
primitive for the "prove it, but don't hand over the customer's data" problem.
* **Zero-knowledge depth.** A real range proof over a hidden score, not a signed claim that still
leaks the number. The score never appears in the proof.
* **Quantum-resistant attestations.** Every proof is Falcon-1024 signed, so the auditable evidence
stays verifiable past the migration to post-quantum cryptography.
* **Zero infrastructure for verifiers.** Verification is a pure function of the proof and the issuer
public key. A counterparty integrates it without standing up a service or holding any of your data.
* **Never fails open.** If the proving service is unreachable, issuance returns an error rather than
a hollow proof; an un-rechecked range proof is reported as unverified, never as a pass.
* **Optionally Substrate 2-bound.** Pair a verified proof with a [Substrate 2](/substrate-2) receipt
to fold it into a signed, audit-ready evidence chain alongside zero-knowledge reputation and
cross-issuer federation.
## How it works
| Step | What happens |
| ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Issue** | Build a no-PII compliance receipt, obtain a zero-knowledge range proof that the score cleared the threshold, and bind both into one Falcon-1024-signed proof envelope. |
| **Verify** | Check the issuer signature and structure from the public key; optionally re-check the range proof and confirm the compliance binding. No PII is ever present. |
| **Share** | Hand the proof to a partner or regulator. They verify the decision independently — and learn nothing about the customer. |
## Cryptography
We're precise about what "post-quantum" covers here:
* **The attestation is post-quantum signed.** The issuer signs each proof envelope with Falcon-1024
(NIST Level 5), offline-verifiable — so a quantum computer cannot forge an attestation or prove a
false result.
* **The zero-knowledge range proof is classical.** The score is hidden with a Bulletproofs range proof
on Ristretto255 (discrete-log based), which is **not** post-quantum. A future quantum computer could,
in principle, recover a committed score from a *captured* proof — but not forge one (the envelope's
Falcon signature is post-quantum), and attestations are short-lived, so the exposure window is bounded.
* **Range-proof verification runs against the prover/verifier you inject**, and the result is surfaced
explicitly — never silently treated as valid when it can't be checked.
* **Roadmap.** A post-quantum zero-knowledge proof system will be adopted when one is standardised.
## Why commercial
The issuer and verifier layer was never published as open source — there is no free tier to fall
back on. It is offered as a **commercial product** because the value is in a maintained,
privacy-preserving compliance capability:
* **Embed without attribution overhead.** A commercial OEM licence lets you ship it inside your own
product with no open-source notice obligations to carry through distribution.
* **Enterprise terms.** Support, warranty, and a defined relationship — the terms procurement and
risk teams expect for a compliance-critical dependency.
* **Maintained crypto suite.** The zero-knowledge proving service and post-quantum primitives are
ongoing work, bundled into the licence rather than inherited.
## Who it's for
* **Regulated PSPs and fintechs** that must evidence compliance to a regulator or partner without
exposing customer PII.
* **Privacy-sensitive marketplaces and B2B platforms** that need to prove a counterparty cleared
screening without sharing the underlying data.
* **Cross-border and inter-institution settlement** that needs a portable, no-PII compliance proof
across jurisdictions.
* Anyone who needs to **prove a compliance decision without disclosing the data behind it**.
## Get Proofs
Proofs is an **additional, separately-licensed package** — an add-on that binds to Substrate 2, not
part of Substrate 2 itself. It is available **self-serve as a Starter licence (perpetual one-time or annual)** (see below) and as a **commercial OEM SDK** and is included in the AlgoVoi
Enterprise and [On-premise](/on-premise) plans. It is not distributed on public package registries.
Starter licence — **perpetual (one-time) or annual subscription**, self-hosted, paid in **USDC** on mainnet; the [store](https://api.algovoi.co.uk/suite-store) shows current pricing for both and issues your licence key + install command on settlement; install from the private index and set `ALGOVOI_LICENSE_KEY` to run. Enterprise / OEM (warranty, indemnity, SLA, multi-deployment, Substrate 2 binding): [email us](mailto:hello@algovoi.co.uk).