The coexistence of heterogeneous sub-networks in 6G poses new security and trust concerns and thus calls for a perimeterless-security model. Blockchain radio access network (B-RAN) provides a trust-building approach via repeated interactions rather than relying on pre-established trust or central authentication. Such a trust-building process naturally supports dynamic trusted services across various service providers (SP) without the need for perimeter-based authentications; however, it remains vulnerable to environmental and system unreliability such as wireless channel uncertainty. In this study, we investigate channel unreliability in the trust-building framework based on repeated interactions for secure wireless services. We derive specific requirements for achieving cooperation between SP and client via a repeated game model and illustrate the implications of channel unreliability on sustaining trusted access services. We consider the framework optimization to guarantee SP-client cooperation, given a worst-case channel condition. Furthermore, we introduce the concept of cooperation region to represent the robustness of the trust-building process and explore the maximum cooperation area to enhance service resilience. Finally, we present simulations to demonstrate the system performance over fading channels and verify our results.

翻译：6G中异构子网的共存带来了新的安全与信任问题，因而需要一种无边界安全模型。区块链无线接入网络（B-RAN）通过重复交互提供了一种信任建立方法，而非依赖预设信任或中心化认证。这种信任建立过程天然支持跨不同服务提供商（SP）的动态可信服务，无需基于边界的认证；然而，它仍易受环境与系统不可靠性（如无线信道不确定性）的影响。本研究基于重复交互的信任建立框架，探究了安全无线服务中的信道不可靠性问题。我们通过重复博弈模型推导出实现SP与客户端合作的具体要求，并阐明了信道不可靠性对维持可信接入服务的影响。考虑最差信道条件，我们对框架进行优化以保证SP-客户端合作。此外，我们引入合作区域概念以表征信任建立过程的鲁棒性，并探索最大合作区域以增强服务韧性。最后，我们通过仿真展示系统在衰落信道上的性能并验证所得结果。