Zero Trust Security Framework for Prosumer-Driven Green Energy Certificates

This paper introduces a hybrid blockchain-DLT framework to enhance the trustworthiness and efficiency of green energy certificates (GECs) by decentralizing control to prosumers (producer-consumers) and adopting a zero-trust security model. The solution integrates Self-Sovereign Identity (SSI) with IOTA’s fee-less Distributed Ledger Technology (DLT) and Concordium’s public blockchain to balance operational costs, transparency, and security.

Key Components of the Framework

1. Self-Sovereign Identity (SSI):

   • Empowers prosumers to autonomously manage their digital identities and issue certificates as Verifiable Credentials (VCs).
   • Replaces centralized Public Key Infrastructure (PKI) with decentralized, cryptographic trust, eliminating reliance on pre-trusted registries.

2. Hybrid DLT-Blockchain Architecture:

   • IOTA Tangle: Handles high-frequency, fee-less transactions at the prosumer level (e.g., certificate issuance and local registry operations).
   • Concordium Blockchain: Anchors Merkle tree root hashes of certificates in bulk, leveraging its built-in SSI features for immutable, global verification.

3. Merkle Tree Structure:

   • Certificates are hashed and stored in a Merkle tree, enabling efficient verification.
   • The root hash of each tree is anchored on Concordium, ensuring data integrity while minimizing blockchain usage (reducing costs).

4. Four Core Entities:

   • Prosumer Meters: Generate and issue GECs as VCs.
   • DLT-driven Registries: Aggregate and validate certificates using IOTA.
   • Concordium Blockchain: Acts as the immutable root of trust.
   • Auditors: Verify certificates via Merkle proofs and blockchain-anchored hashes.

How the Framework Works

Certificate Issuance (Steps 1–4):

1. Prosumer Meters generate GECs as SSI-based VCs and send them to registries.
2. Registries validate VCs, build Merkle trees, and anchor root hashes on Concordium.
3. Merkle trees are stored locally on IOTA, with only root hashes committed to the blockchain.

Certificate Verification (Steps 5–6):

1. Prosumers submit certificates and Merkle trees (as Verifiable Presentations, VPs) to auditors.
2. Auditors verify certificates by reconstructing Merkle proofs and cross-checking root hashes on Concordium.

Advantages Over Existing Systems

1. Decentralized Trust:

   • Shifts trust from centralized registries to decentralized prosumers, aligning with zero-trust principles.

2. Cost Efficiency:

   • IOTA’s fee-less DLT reduces operational costs for high-volume prosumer transactions, while Concordium’s bulk anchoring minimizes blockchain fees.

3. Enhanced Security & Transparency:

   • SSI ensures tamper-proof identity management, while Merkle trees and blockchain anchoring guarantee certificate integrity.

4. Scalability:

   • Hybrid architecture supports large-scale prosumer participation without compromising performance.

5. Interoperability:

   • Combines the strengths of DLT (speed, cost) and blockchain (immutability, SSI) for a flexible, future-proof system.