Retraction Notice: Distributed AI and Blockchain for 6G-Assisted Terrestrial and Non-Terrestrial Networks: Challenges and Future Directions

The integration of Terrestrial and Non-Terrestrial Networks (TNTNs) with the sixth-generation (6G) wireless ecosystem will revolutionize the futuristic communication networks by enabling comprehensive interconnection and quality of service. However, such an integrated network will raise serious security and privacy issues due to the insecure communication among untrusted participating entities over an open unsecured public channel. As a result, the entire ecosystem can be accessed by both legitimate users and adversaries. Distributed AI when integrated with blockchain has a great potential to provide a feasible alternative to solve the security and privacy issues of 6G-assisted TNTNs. As a case study, a distributed AI is first adopted to cooperatively participate in the training process of a global model directly on devices. This approach ensures privacy and security of user data, and also confirms that only valid data is used by smart contracts to execute consensus mechanism. The multiple parallel blockchain are employed to securely and efficiently manage, and share data at each layer of 6G-assisted TNTNs. The efficiency of the proposed framework is demonstrated by numerical findings. Finally, prospective open research issues in employing distributed AI and blockchain for 6G-assisted TNTNs are highlighted.