DLT-EVA: Hardening O-RAN Auditing and Digital Evidence Preservation Through Blockchain

The open radio access network (O-RAN) includes innovative building blocks, like the near-real time RAN intelligent controller and extensible applications, among others, that provide effective management of the communications infrastructure and services. The integration of potentially untrusted thirdparty applications raises significant security concerns, while the transition to softwarized networks driven by network function virtualization extends O-RAN attack surface and increases the threats to consider. Although security event logging contributes to adversarial behavior detection in O-RAN, an elaborate log management architecture for the secure preservation of important security event information is still at its early stages. In this paper, we propose a blockchain-enabled framework, referred to as DLTEVA, for trusted digital evidence preservation and auditing in O-RAN that employs advanced remote attestation techniques and secure distributed log management. It is shown how the proposed framework is capable of defending against sophisticated cyberattacks on remote attestation systems, therefore ensuring the secure operation of critical O-RAN applications and services.