The era of the 5th generation mobile networks and wireless systems (in short 5G) has come. 5G is being adopted for commercial use. Nowadays, researchers and practitioners have moved ahead to discuss beyond 5G and 6G telecommunication technologies. In December 2018, the 1st IEEE Summit on 6G was held in Levi, Finland to discuss basic concepts, proposals, and suggestions for 6G, summarized in a white paper. The idea of 6G was crystallized in a slogan: 6G is about the 6th sense. 6G follows in the footsteps of vertical market use of 5G and pursues the merging of communication and sensing. The purpose is to sense and understand the physical world and biological beings and be able to program them, giving rise to automation systems that span a rich variety of devices, several types of network technologies, and humans. This will be a prerequisite for an unprecedented level of automation in industry, in logistics, mobility, health, and more. As a consequence, physical safety will depend on network and information security. Anticipating the development, ITU-T specifies that Trustworthy Networking should be provided, which drives us to pursue a trust management solution to support trustworthy networking in packet networks. Especially advocated by some governments like US and China, 6G could be a large-scale heterogeneous network (LS-HetNet) that integrates space satellite networks, terrestrial networks, marine networks and merge different types of networks into a large-scale integrated network. Such a network can support anywhere and anytime networking with high Quality-of-Service meeting mobile user expectations and be robust against hardware, software, and configuration failures and malicious activities.

A LS-HetNet merges different types of networks including the Internet, mobile cellular networks, satellite networks, marine networks, etc. Different from traditional isomorphic networks and other HetNets, a LS-HetNet, e.g., Space-Terrestrial-Marine Integrated Networks in another term, holds such characteristics as heterogeneity, distribution, multi-operator domains, dynamic topology, self- organization, openness, high latency and scalability. The network functionality is being virtualized and thus runs on cloud platforms, widening the bounds of technical feasibility and allowing new business models. These specific characteristics introduce new challenges to network management and orchestration causing severe security, privacy, and trust threats in many aspects, for example, identity management, trustworthy network access and handover, secure and trustworthy routing, Authentication/Authorization/ Accounting (AAA) management, secure data transmission and key management, especially end-to-end secure communications. Apart from the above, privacy protection becomes crucially important to preserve user identity privacy, personal information privacy, and communication data privacy. In addition, a trustworthy mobile terminal is highly expected to support secure, trustworthy, and highly available HetNet communications. However, the current literature normally focuses on specific types of HetNet, such as wireless HetNet, sensor HetNet, and cellular HetNet, lacking support for generality and universality. Existing solutions normally apply a centralized network management framework to realize secure authentication and management by relying on some trusted parties and thus cannot afford single-point failure and internal hackers. When it comes to device or host security and protection from hacking, the current approach leaves the responsibility to the device itself, leading to fragmentation of security operations and management with a low level of automation and ignoring the lack of expertise in user communities. Current approaches cannot support end to end trust, user identity, and routing trust in a uniform way with high scalability and applicability to all use cases. Programming the world without endangering safety requires a LS-HetNet and devices that can be trusted to perform as expected automatically and intelligently even under threats from malicious actors.

This Special Issue aims to bring together recent advances in trustworthy networking in the context of beyond 5G and 6G networks. It welcomes original and innovative research on theories, methodologies, schemes, algorithms, and prototype systems related to trustworthy networking from academia, industry, and government. In addition, review articles discussing the current state of the art are welcomed.

Potential topics include but are not limited to the following:

• Theories, frameworks, architectures, and systems for trustworthy networking
• Identification, naming, authentication, authorization, and accounting in trustworthy HetNets
• Trustworthy HetNet routing
• Network data collection and analysis for trustworthy networking
• Inter-operator security and trust protocols
• End-to-end security and trust
• Handover security and privacy
• Threat and intrusion detection in integrated HetNets
• Security and privacy protection in integrated HetNets
• HetNet trust enforcement and management
• Network data trust management
• Trustworthy slicing in integrated HetNets
• Intent based communications and network zoning
• Machine learning for trustworthy networking
• Blockchain and trustworthy networking