A Novel Secure Split Federated Semantic Learning Framework and its Optimization for Digital Twin Network Evolution

This paper introduces a novel secure split federated semantic learning (SFsL) framework to facilitate the maintenance and evolution of digital twin networks (DTNs). Efficiently updating and evolving DTNs generally involves several critical processes: semantic extraction and transmission for physical-to-virtual synchronization, virtual model transformation and verification, and ensuring the security and privacy of physical entity data. While conventional semantic communication frameworks can effectively address semantic extraction and transmission, the complexities of virtual model transformation, verification, and data security demand a more comprehensive approach. To address these challenges, the proposed SFsL framework integrates split federated learning with task-oriented secure semantic communication schemes. In addition, it incorporates a token-based semantic defence method to distinguish between adversarial and authentic semantic data and an asynchronous secure model aggregation mechanism to enhance data-sharing efficiency. The system reliability is then formulated as a stochastic optimization problem, aiming to minimize cost complexity while maintaining high accuracy during periodic model aggregation. Evaluation results, obtained using performance metrics such as privacy loss, experienced loss, accuracy, cost and reliability, demonstrate that the SFsL framework outperforms other commonly adopted security and privacy schemes, offering improved efficiency towards the maintenance and evolution of such dynamic systems. This highlights the capability of SFsL to enable adaptive, efficient and reliable network evolutions when deployed in practical DTNs with dynamic resource constraints.