A Lightweight Multi-BS Cooperation AKA Mechanism for Fully Decoupled RAN

The fully decoupled radio access network (FD-RAN) divides the base station (BS) into three components: 1) the uplink data BS (UBS); 2) the downlink data BS (DBS); and 3) the control BS (CBS) to achieve an ultra flexible network. FD-RAN can easily realize dynamic multi-BS cooperation to boost throughput and guarantee users’ quality of experience. However, as the number of cooperating BSs and concurrently accessed Internet of Things (IoT) devices increases, significant authentication and key agreement (AKA) overheads will be incurred, and the system becomes vulnerable to various security threats. This article proposes a novel lightweight AKA protocol that employs secret value sharing for secure key negotiation among BSs, user equipment and the core network (CN). Furthermore, multidevice of IoT access is optimized through aggregated message authentication codes with detecting functionality (AMAD) to efficiently manage and aggregate access requests. By utilizing interpolation polynomials and multiparty key agreement techniques, the proposed solution improves key negotiation efficiency while mitigating risks from man-in-the-middle (MitM) and Distributed Denial of Service (DDoS) attacks. Security analyses are conducted to validate the protocol while showcasing its superiority on computation, communication and transmission efficiency.