O-Cloud Security: A Comprehensive Survey of Threats, Mitigation Strategies, and Future Directions

The Open Radio Access Network (O-RAN) represents a groundbreaking evolution in next-generation (NGN) communication systems, offering an open, flexible, and vendor-agnostic approach that disaggregates traditional network functions. Central to this ecosystem is the O-Cloud, which serves as the foundation for hosting and managing virtualized and containerized network functions in a cloud-native environment. However, while the O-Cloud offers significant advantages in scalability and efficiency, it also introduces unique security challenges, integrating a whole paradigm of telecom and cloud computing. This survey provides a comprehensive analysis of security measures tailored to the unique needs of O-Cloud environments. Further, we thoroughly detail the existing threats, highlight the vulnerabilities, and discuss the emerging security mitigation techniques. We analyze both foundational and emerging security solutions, detailing current threats and vulnerabilities while presenting innovative mitigation techniques. In particular, we will inspect the impact of advanced technologies such as zero-trust architecture (ZTA), Secure Access Service Edge (SASE), proof of retrievability (PoR), machine learning (ML), secure generative AI, secure caching, blockchain, digital twin (DT), and Quantum security technologies in strengthening the O-Cloud security. Through this analysis, we aim to provide an in-depth survey aimed at strengthening O-Cloud-based telecom networks against cybersecurity threats and ensuring data and services’ integrity. Our insights and forward-looking recommendations for O-Cloud security are presented to develop a resilient and secure O-Cloud environment, offering directional guidance to practitioners and researchers and a strategic roadmap for the stakeholders to build a secure and sustainable O-Cloud environment.