Mechanism and Primitive Description
The lifecycle-carbon-balance attestation is constructed as a deterministic function over a directed acyclic graph of upstream attestations. Each upstream attestation contributes a signed scalar contribution to one of four terms: embodied carbon (E), sequestered carbon (S), methane-avoidance credit (M), and end-of-life recovered carbon (R). The balance is computed as the equation balance = E − S − M − R, where positive values denote net atmospheric emission and negative values denote net atmospheric removal. The composite attestation is itself a signed object containing the four constituent scalars, the cryptographic hashes of every upstream attestation in the lineage chain, and the signing key of the issuing party.
Embodied carbon E aggregates upstream cement-clinker production emissions, transport emissions across the supply chain, and process-energy emissions during fabrication. Each component enters as a separately signed attestation from a credentialed supplier, and the embodied total is the cryptographically verifiable sum across those upstream signatures. Sequestered carbon S aggregates the biomass-derived graphene fraction's photosynthetic uptake, computed from the feedstock-mass attestation and the conversion-yield attestation supplied by the carbon-substrate-flow processor. Methane-avoidance credit M captures the CO₂-equivalent of methane emission that would have occurred had the biomass feedstock decomposed in an open-air or landfill pathway; M is computed by reference to a feedstock-origin attestation that classifies the counterfactual disposal pathway. End-of-life recovered carbon R aggregates the carbon mass returned to a closed loop at end-of-life, supplied by a recovery-facility attestation issued upon physical receipt of the recovered material.
The four terms are independent, additively combined, and individually verifiable. The composite attestation does not require any party to assert all four terms simultaneously; each term is constructed from upstream signatures rooted in different credentialed bodies, and the composite issuer's role is purely arithmetic and cryptographic, to bind the four roots and the resulting balance into a single signed object.
Operating Parameters and Engineering Envelope
The disclosed primitive identifies a net-negative operating region defined by two principal parameters: biomass loading and recovery efficiency. Biomass loading is the mass fraction of the structural material composed of biomass-derived graphene; recovery efficiency is the fraction of the original carbon mass returned to closed loop at end-of-life. Above approximately 5 weight percent biomass loading and 70 percent recovery efficiency, the four-term balance becomes net-negative, the unit removes more atmospheric carbon than it embodies, across the parameter range characteristic of cementitious host materials at industrial scale. The 5 wt% and 70% thresholds are not absolute; they shift with embodied-carbon intensity of the cement supply (low-clinker blends shift the threshold downward), with transport distance (regional supply chains shift it downward), and with the methane-avoidance counterfactual classification (high-methane feedstocks such as wet food waste shift it substantially downward).
The attestation is parameterized by the same scalars and admits arbitrary points in the parameter space; it does not enforce the net-negative region as a precondition for issuance. Rather, it issues a signed balance for any input combination, and downstream consumers (including carbon-credit registries) apply their own thresholds. This separation of accounting from policy is structural: the attestation is a measurement primitive, not a regulatory one.
Numerical envelope: embodied-carbon contributions span roughly 0.6 to 0.9 kg CO₂-eq per kg cement clinker, transport contributions span 0.01 to 0.10 kg CO₂-eq per kg per 1000 km, and process-energy contributions are bounded by the grid carbon intensity at the fabrication location. Sequestered carbon enters at approximately 3.67 kg CO₂-eq per kg fixed carbon (the stoichiometric ratio of CO₂ to C). Methane-avoidance contributions are scaled by the global-warming-potential factor for methane (GWP100 ≈ 28–34) applied to the avoided methane mass; end-of-life recovery contributions are bounded by the conserved carbon mass of the original unit.
Alternative Embodiments
Several embodiments of the attestation primitive remain within the disclosed scope. A first embodiment binds the four terms in a Merkle-tree structure with each upstream attestation appearing as a leaf; the composite signature commits to the root, and verification proceeds by Merkle proof against the published root. A second embodiment uses a flat list of upstream signatures rather than a tree, trading verification efficiency for issuance simplicity. A third embodiment splits the composite attestation into per-term sub-attestations, each independently signed and recombined at registry-ingestion time.
Time-axis embodiments are also disclosed. A static embodiment computes the balance once at fabrication and treats the result as final; a dynamic embodiment re-issues the balance at end-of-life with the recovery term updated against the actual recovery attestation. A streaming embodiment issues partial balances at intermediate lifecycle events (initial fabrication, deployment, mid-life inspection, recovery), each cryptographically chained to the previous, supporting registry primitives that require live updates.
Composition with Adjacent Primitives
The lifecycle-carbon-balance attestation composes with the carbon-credit registry primitive disclosed under the same parent provisional. A registry consumes the composite attestation, validates the four upstream signature roots, and issues a registry-internal credit object that references the composite attestation by hash. The credit object is then transferable on the registry's transfer ledger without further reference to the upstream lineage chain, but at any time the credit object can be unwound by following the hash reference back to the composite attestation and its upstream constituents.
The attestation also composes with the biomass-feedstock-diversity primitive (admitting any of five feedstock classes as input to the sequestered-carbon term) and with the carbon-bound-cell primitive disclosed under U.S. Provisional 64/052,368, where the cell's carbon framework can be sourced from the same biomass lineage chain. In this configuration, the cell inherits a sequestered-carbon attestation through the same composite primitive used by the structural-material disclosure, providing a unified attestation surface across both products.
Prior-Art Distinctions
Existing lifecycle-assessment standards (ISO 14040, ISO 14067, the EN 15804 standard for construction products) define the conceptual scope of cradle-to-grave carbon accounting but do not specify a cryptographic verification mechanism, do not enforce composite signing across upstream attestations, and do not define a net-negative operating region as a class. Existing carbon-credit registries (Verra VCS, Gold Standard, the various compliance registries) admit attestations from credentialed verifiers but treat the verifier's signature as the trust anchor; the upstream lineage is not cryptographically chained, and the registry consumer cannot independently re-verify the upstream attestations.
The disclosed attestation differs structurally on three axes. First, the trust anchor is distributed across the upstream signatures rather than concentrated at the verifier; no single-point trust is required. Second, the four-term decomposition is enforced at the cryptographic layer, not merely at the documentary layer; a composite attestation that omits any term is cryptographically distinguishable from a complete one. Third, the methane-avoidance credit is an integral term of the balance rather than an auxiliary computation, and its inclusion is structural: the disclosed primitive cannot be reduced to a three-term embodied-minus-sequestered accounting without changing class.
Disclosure Scope
The disclosure extends to any composite attestation whose verification requires walk-through of independently signed upstream attestations across the four enumerated terms. Embodiments that omit one or more terms (for example, a three-term variant lacking methane-avoidance) fall outside the disclosed primitive but may fall within an explicitly broadened genus claim. Embodiments that add additional terms (for example, a fifth term for biogenic decay during deployment) remain within the disclosed scope provided the four core terms are preserved.
The cryptographic embodiment is not limited to any particular signature algorithm or hash function; the disclosure is at the level of the data structure (signed composite, hash-bound upstream lineage, four-term decomposition) rather than at the level of cryptographic primitive selection. Implementations using Ed25519, ECDSA, or post-quantum schemes are equivalent under the disclosure, as are implementations using SHA-256, SHA-3, or BLAKE3 as the hashing primitive.
The attestation is intended to compose with carbon-credit registry primitives in a manner that preserves the registry's existing transfer mechanics while adding cryptographic verifiability of the upstream lineage. The disclosure scope expressly includes both standalone-attestation and registry-integrated embodiments. The parent provisional, U.S. Provisional Application 64/050,895, is incorporated by reference for the formal definitions of each term and the canonical encoding of the composite attestation.
The disclosure further contemplates batched and unitized attestations. A unit-level embodiment issues one composite attestation per discrete structural-material unit (one precast panel, one beam, one batch of mortar); a batch-level embodiment issues one attestation per production lot, with downstream apportionment of the balance across units handled by a separate apportionment attestation. Both embodiments are within scope; the choice between them is governed by the granularity of the upstream supplier attestations and by the registry consumer's apportionment requirements.
The disclosure addresses revocation and amendment. An issued composite attestation may be superseded by a later-dated attestation referencing the same structural-material unit by a stable identifier; the lineage chain preserves both attestations and the registry consumer treats the latest non-revoked attestation as authoritative. Where an upstream attestation in the lineage is itself revoked (for example, where a feedstock-origin attestation is withdrawn by the credentialing body), the composite attestation transitively loses verifiability and the registry consumer is expected to treat the affected balance as unsupported. This revocation propagation is a structural feature of the cryptographic-chain construction and is not a separate primitive.
The disclosure is intended to be construed broadly to cover any composite attestation satisfying the four-term decomposition and the cryptographic-chain construction, regardless of implementation language, transport encoding, or registry integration profile. Equivalents under the doctrine include attestations that achieve the same accounting decomposition under a different surface syntax, provided the underlying four-term structure and the upstream-signature dependence are preserved.
The disclosure recognizes that downstream registry consumers may impose additional accounting overlays: for example, a permanence discount applied to the sequestered-carbon term to reflect the expected service life of the structural material, or a conservativeness factor applied to the methane-avoidance term to reflect uncertainty in the counterfactual classification. These overlays are downstream of the disclosed primitive and do not affect its class membership. The composite attestation's role is to deliver verifiable raw scalars; the registry's role is to apply policy. The disclosed scope expressly excludes the registry-policy overlay from the primitive itself, preserving the separation of measurement from policy that is structural to the disclosure.
The disclosure also contemplates jurisdictional variation in the recognized credentialing bodies. The composite attestation does not enumerate or restrict the set of acceptable upstream credentialing bodies; the registry consumer applies its own acceptance list, and the same composite attestation may be accepted by one registry and rejected by another based on differing credentialing-body acceptance criteria. This jurisdictional flexibility is a structural feature of the cryptographic-chain construction: the primitive verifies that a signature is valid and that it chains to the asserted upstream root, but it does not assert that the signing body is itself authoritative, that determination is delegated to the registry consumer's policy layer.
