Securing the 6G Space–Air–Ground Integrated Network (6G SAGIN)

The ETSI Security Conference 2025 brought together experts from across the telecom and technology ecosystem to discuss the latest research and emerging challenges in securing next-generation communication systems. Among the highlights was a presentation by Leyi Zhang from ZTE, who explored how to secure the Space–Air–Ground Integrated Network (SAGIN), a cornerstone concept for 6G.

SAGIN is envisioned as the backbone of 6G connectivity, combining ground networks with high-altitude platforms and satellites to create a holistic, three-dimensional communication fabric. This architecture promises global coverage, ultra-low latency and massive connectivity for diverse applications ranging from industrial automation to remote sensing. However, the same characteristics that make it powerful also make it vulnerable to new and evolving threats.

Zhang explained that the SAGIN security landscape varies depending on whether satellites operate in transparent or regenerative payload modes. In the transparent mode, satellites act as simple relays forwarding signals between terminals and ground networks. This model faces risks such as data eavesdropping, signal interference and false gateway attacks. Regenerative payloads, where some or all network elements are moved onboard the satellite, introduce new complexities in securing on-board base stations, inter-satellite links and remote operations.

Emerging technologies add further uncertainty. Quantum computing could render today’s cryptographic algorithms obsolete, while decentralised and dynamic topologies challenge the use of traditional trust models such as centralised PKI. The introduction of AI and machine learning, though promising for predictive threat detection and automated defence, also opens new avenues for adversarial attacks that can manipulate models or evade detection.

ZTE’s proposed framework addresses these challenges across multiple layers. Communication security is ensured through optimised encryption and integrity algorithms that safeguard the air interface, feeder and inter-satellite links. Authentication mechanisms are designed for scalability, supporting mutual and group authentication to handle massive numbers of devices, especially in satellite IoT deployments. Secure handovers, trusted execution environments, anti-jamming techniques and remote maintenance safeguards further strengthen resilience.

Lightweight security plays a central role, given the limited computational resources of space-based nodes. Techniques such as physical-layer security (PLS) use the randomness and time-varying nature of radio channels as a built-in source of protection, reducing the dependence on heavy cryptographic operations. Multi-fingerprint methods, including channel, beam and RF fingerprints, enable key generation and authentication that are inherently resistant to eavesdropping.

Standardisation remains an essential part of making SAGIN security practical and interoperable. The 3GPP non-terrestrial network (NTN) evolution from Release 15 through to Release 21 illustrates the steady progression from basic satellite integration to full regenerative payload support. In parallel, ITU-T Study Group 17 is developing guidelines and reports that address the convergence of fixed, mobile and satellite systems under IMT-2030.

Looking ahead, the focus areas for 6G security research and standardisation include lightweight authentication protocols, post-quantum cryptography, AI-driven adaptive defences, decentralised trust frameworks and cross-layer security designs that unify protection from the physical to the application layer.

The security of 6G SAGIN is not simply an add-on feature but a fundamental design principle. As networks extend into the skies and beyond, ensuring confidentiality, integrity and trust across heterogeneous and dynamic environments will define the reliability and adoption of future 6G systems.

Leyi Zhang’s presentation “Secure Space–Air–Ground Integrated Network: Advancing 6G Network Security” is available here.

Related Posts: 

Posted by on

Comments

Post a Comment