Sustainability-First Distributed Ledger Systems: Six Reference Designs and a Shared SFC Engineering Profile

Six original distributed-ledger system designs addressing ecological challenges across supply-chain
certification, healthcare and pharmacy interchange, paperless billing, recycling and material recovery,
cross-operator roaming for telecom and EV charging, and carbon-credit measurement, reporting and
verification.

All six share a single Sustainability-First Consensus (SFC) engineering profile that turns sustainability
criteria into verifiable engineering properties rather than claims: an annual network energy budget,
hardware-lifecycle constraints excluding single-use hardware, signed on-chain EnergyAttested and
CarbonAttested events carrying a Net-Zero invariant, a conformance API for machine-readable disclosure
aligned to CSRD and ESRS-E1, and a qualification rule separating hot-path ledgers from anchor-only layers.

Each project is documented as four companion files: README (motivation, architecture, data flow,
sustainability and policy alignment), PRD (problem, personas, requirements, KPIs, milestones), SPEC
(identifiers, schemas, event envelope, REST API, smart contracts, conformance tests) and ARCH
(components, sequences, trust boundaries, deployment, failure modes), with architecture and data-flow
diagrams.

All work is documented at design level. No system described here is implemented or deployed, and no
figure in these documents is a measurement of a running system; values are design targets or are cited
from published external sources.

This deposit records the engineering profile and the six architectures that apply it. The underlying
four-criterion framework is defined separately in Besleaga (2026), "Sustainability-First Consensus"
Ledgers for a Green Digital Future, Association for Computing Machinery, doi:10.1145/3809296 (accepted;
in press). Deployments building on these designs should cite both.