Secure IoT Communication and Policy Enforcement Framework (SCOPE)

Abstract

Time-sensitive Internet of Things (IoT) deployments need fine-grained, auditable authorisation without exposing payloads to intermediaries or embedding access policy in cipher-text. The Secure IoT Communication and Policy Enforcement (SCOPE) framework separates on-ledger authorisation from end-to-end content protection while keeping intermediaries minimally trusted. The SCOPE framework comprises a Broker Smart Contract (BSC) that records authorisation decisions, a decentralised Trusted Authority (TA) that issues committee attestations and epoch-scoped revocation snapshots, and a stateless edge relay that verifies requests and forwards ciphertext without decryption. Payload confidentiality and integrity are provided end-to-end by a pairing-free authenticated encryption with associated data (AEAD) channel with ephemeral key agreement and disciplined nonces, yielding replay resistance and forward secrecy with respect to the sender’s key. A prototype on a permissioned distributed ledger runtime, evaluated on an IoT edge testbed, demonstrates sub-second end-to-end operation, on-ledger authorisation within 500 ms, and lower computational latency than pairing-based Ciphertext-Policy Attribute-Based Encryption and Attribute-Based Signcryption (CP-ABE/ABSC) baselines, including BLUMA (multi-authority CP-ABE with hidden policy). The design is portable across ledgers and supports a drop-in post-quantum key-encapsulation mechanism plus AEAD (KEM+AEAD) channel without changes to the policy or relay planes, enabling auditable authorisation for multi-stakeholder settings such as smart ports, industrial automation, and e-health.