IoTAuth: A Decentralized Cross-chain Identity Authentication Scheme for 6G Non-Terrestrial IoT Networks

The upcoming 6G Non-Terrestrial Networks (NTN) technology is expected to enable comprehensive connectivity of the Internet of Things (IoT) across various environments. The presence of a large number of IoT devices operating in diverse scenarios, along with the associated vast amounts of data, poses challenges in terms of security and privacy for the 6G NTN IoT networks. Therefore, blockchain technology is considered a key solution for enhancing network security and simplifying management in 6G networks. While IoT devices usually adopt heterogeneous blockchain platforms in different scenarios, cross-chain identity authentication technology is a prerequisite for secure interactions. However, traditional authentication techniques, such as PKI-based solutions, face challenges in handling authentication within 6G Non-Terrestrial Networks, since techniques heavily rely on trusted third-party certificate authorities (CAs) to issue credentials across blockchains. In response to these challenges, we propose a decentralized cross-chain identity authentication scheme for 6G NTN IoT networks called IoTAuth. We design a novel authentication mechanism with user autonomy, combining threshold signatures and DID technology to transform the process of identity credential issuance into a collaborative issuance by multiple nodes under the 6G NTN IoT networks. Furthermore, the scheme realizes cross-chain identity authentication without a centralized manner via an identity conversion mechanism based on relay-chain technology, which further guarantees security in the 6G NTN IoT networks context. The experimental results illustrate the effectiveness and practicality of the scheme. Finally, we present comprehensive future directions.