A Secure Access Framework for IoT–Cloud Integration With Blockchain and Bi‐GCN

Digital advancements have made cloud computing and IoT essential for innovative environments such as healthcare and industry. Cloud platforms offer scalable compute and storage capabilities, whereas IoT devices generate real‐time data. However, there are significant challenges faced while integrating the IoT with cloud to achieve robust, scalable, and secure access control. Traditional centralized models, such as static rule‐based mechanisms and public key infrastructure (PKI), are prone to single points of failure and suffer from limited scalability and poor adaptability. To address these issues, this paper proposes a decentralized access control architecture that combines blockchain with a hybrid bidirectional graph convolutional network (Bi‐GCN). The framework integrates ciphertext policy‐attribute based encryption (CP‐ABE) with trusted platform module (TPM)–based pseudonymous identities and the blockchain smart contracts for fine‐ and hardware‐assisted access control. A generative adversarial network (GAN)‐assisted prevalidation layer filters sybil, tampering, and spoofing attempts before block inclusion, enhancing integrity and reducing overhead. Bi‐GCN supports real‐time anomaly detection, trust adaptation, and behavior profiling, while smart contracts enforce adaptive role‐attribute policies. Experimental results show that the proposed model outperforms existing methods across key metrics, including 0.97 accuracy, 0.98 F ‐measure, and minimal security overhead of 0.7%. Although it introduces slight latency due to advanced processing, the benefits of secure and intelligent access management outweigh the trade‐off. The integration of blockchain ensures decentralized and immutable policy enforcement, while Bi‐GCN facilitates self‐adaptive security, making the architecture suitable for dynamic IoT–cloud ecosystems.