BAT-CA: A Blockchain-Based Anonymous and Traceable Cross-Domain Authentication Approach for Interner of Things

With the growing interconnectivity in Internet of Things (IoT) fields like smart home, smart city, and Internet of Vehicles (IoV), the need for secure cross-domain authentication is crucial. Existing methods face issues such as centralized control, high overhead, and lack of anonymity and traceability. To address these issues, we propose BAT-CA, a blockchain-based crossdomain authentication solution. BAT-CA utilizes a consortium blockchain for decentralized authentication, leveraging public key hash addresses for anonymity and traceability. This approach includes intra-domain and cross-domain authentication methods tailored for devices within domains and across domains. Intradomain authentication leverages Schnorr signatures to incorporate domain node endorsement proofs for secure and efficient authentication. For cross-domain authentication, a transaction token based on blockchain transaction structures is designed, combining distributed key generation and aggregated threshold signatures. Device real IDs are encrypted and stored on the blockchain, enabling anonymous device traceability through decrypted fragments collected from domain node voting. A series of experiments in physical environments validate the effectiveness and efficiency of the proposed approach.