Blockchain Meets O-RAN: A Decentralized Zero-Trust Framework for Secure and Resilient O-RAN in 6G and Beyond

O-RAN (Open Radio Access Network) is an initiative that promotes the development of open and interoperable radio access technologies. The O-RAN Alliance has undertaken specification efforts that align with O-RAN principles, incorporating the near-real-time RAN Intelligent Controller (RIC) to manage extensible applications (xApps) owned by various ORAN operators and vendors. However, this integration of untrusted third-party applications raises significant security concerns, expanding the threat surface of 6G networks. Moreover, the heterogeneity in deployment, with apps residing on various sites, poses challenges for traditional security models based on perimeter security. To overcome this issue, a Zero Trust Architecture (ZTA) becomes paramount to ensure network security. In this context, we introduce TrustORAN, a novel blockchain-based decentralized Zero-Trust Framework designed to ensure security and trustworthiness in O-RAN. TrustORAN allows for the verification and authentication of xApps by O-RAN players, to prevent unauthorized access from malicious xApps. Moreover, we introduce a dynamic decentralized-based access control framework that allows vendors to manage permissions in a fully decentralized, flexible, scalable, and secure manner. TrustORAN architecture is implemented, tested, and deployed on both private and public blockchains. The obtained results demonstrate that TrustORAN empowers 6G O-RAN networks with heightened security, resilience, and robustness, providing effective protection against evolving security threats while ensuring Trust.