CBAM Supplier Attestation
Chain country, origin, and carbon-intensity attributes required by EU CBAM as cryptographic attestations — without exposing supplier raw data or trade secrets.
Who this is for.
Your business exports to the EU, or sits inside the EU as an importer for products in CBAM-covered categories. The 2026 reporting cycle is no longer a forecast — auditors are starting to ask for evidence, and your suppliers are starting to ask why they have to share more than they used to.
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Regulatory-affairs leads at manufacturers exporting steel, aluminum, cement, or fertilizer to the EU
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Procurement leads gathering CBAM evidence from upstream suppliers, including multi-tier suppliers they don't directly contract with
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Risk and trade-compliance owners balancing supplier confidentiality against EU regulatory exposure
Hand over the source, or just the facts?
production data, cost and supplier-internal dealings
meets CBAM-required country, origin and carbon-intensity attributes
Each tier of the chain — the smelter, the rolling mill, the trader, the importer — issues attestations for the attributes CBAM actually checks: country of production, carbon intensity, the regulatory regime the attribute was measured against. The attributes are signed against each supplier's reference data (production logs, energy mix, monitoring system output), but the proof reveals only the attribute, never the underlying source.
Downstream parties verify the attestation directly. A trader chaining steel from a smelter to an EU importer doesn't need the smelter's production data — it needs proof that the smelter's reported carbon intensity holds under CBAM's measurement scheme. When that proof is a ZK attestation rather than a PDF, the trader can compose it with their own attestation and pass a single chained proof to the importer.
The result is that CBAM evidence becomes a cryptographic chain instead of a document-discovery exercise — and each link controls exactly what flows downstream.
Choose on three criteria.
Only work that needs all three at once — pass without exposing, independent verification, tamper-proof — is Lemma's domain.
| Method | Pass without exposing | Independent verification | Tamper-proof |
|---|---|---|---|
| Access control only | △ | ✗ | ✗ |
| Masking / anonymization | △ | ✗ | ✗ |
| Encryption only | ✓ | ✗ | ✗ |
| Lemma (ZK proof)the only one with all 3 | ✓ | ✓ | ✓ |
How it works
Tell us where your CBAM evidence is concentrating risk today — which category, which supplier tier, which counterparty disclosure conversation has stalled. We'll explore together whether per-attribute attestation could fit. No supplier data or production methodology required.
Related use cases
The bigger picture
The bigger picture this use case belongs to.
We map use scenarios across industries and workflows by the four axes.
See use scenarios for Regulatory Attribute in Solutions →TRY LEMMA
Run it yourself.
No sales call needed — start hands-on with Lemma's products.