Public Procurement Attestation
Verify supplier origin, track record, and eligibility attributes for public procurement via ZK attestations with no raw-document submission, so buyers can confirm the requirements are met while bidders keep their originals and protect proprietary information.
For public-procurement teams
Remove the asymmetry that makes buyers take custody of documents and bidders over-disclose — by proving only the eligibility the evaluation actually checks.
-
Procurement leads at municipalities and central-government buyers
-
Procurement-policy designers operationalizing eligibility schemas across multiple tenders
-
Defense and critical-infrastructure suppliers protecting financial, technical, or personnel data while bidding
Hand over the source, or just the facts?
Nothing changes on the floor. Everything changes for the receiver.
① Your team just saves, as always.
- The usual step
- Fill in the record and save
- On save
- A proof is attached (API, behind the scenes)
- The document itself
- never sent
② They just open a link.
- Proven fact
- meets the tender's eligibility requirements
- the bidder's raw documents and performance internals
- not shown
- Login / keys
- not needed
- The document stays private — the record itself is never sent or disclosed.
- Independent verification — the receiver just opens a link. No account, no keys.
- Edits are detected — even a one-character edit fails verification.
The bidder collects per-attribute attestations against its own records: ISO certifications from the certifying body, financial-eligibility attestations from its auditor, track-record attestations against its own work history (or aggregated through an industry registry). Each attribute is signed by the issuer the procurement policy already trusts.
The bid carries a composed ZK proof against the tender's eligibility schema. The evaluator verifies the predicate — "the bidder holds an active ISO 14001 certification, meets the financial threshold for this tender class, and has at least N similar references in the last 5 years" — without ever holding the underlying certificates, balance sheets, or reference letters.
For consortia bids, prime contractors compose sub-supplier attestations the same way they compose their own. The evaluator sees one chained proof and verifies the consortium-level eligibility predicate without scanning sub-supplier records.
Why the usual methods fall short.
Only work that needs all three at once — pass without exposing, independent verification, tamper-evidence — is Lemma's domain.
| Method | Pass without exposing | Independent verification | Tamper-evident | What happens |
|---|---|---|---|---|
| Access control / permissions | △ | ✗ | ✗ | “Someone inside could have edited it” remains possible |
| Masking / redacted copies | △ | ✗ | ✗ | Redaction work grows; the original is still unproven |
| Encrypt and store / send | ✓ | ✗ | ✗ | To verify, the receiver needs it disclosed after all |
| Lemma (ZK proof)the only one with all 3 | ✓ | ✓ | ✓ | The receiver just opens a link |
How it works — and how to start.
We help design disclosure scope and retention, run the PoC, and support production.
Start with a 30-minute call.
Tell us one tender where the disclosure surface concentrates risk, in the first 30 minutes. No tender documentation or bidder data required.
Find the case that matches your industry and problem
Browse all 36 use cases →TRY LEMMA
Run it yourself.
No sales call needed — start hands-on with Lemma's products.