A Comprehensive Review of Delay-Aware Encryption Scheduling in Satellite Backbone Links: Security Models, Optimization Techniques, and Emerging Computing Applications

Abstract

Satellite backbone links play a crucial role in enabling global communication, especially in remote and infrastructure-limited regions, but they face significant challenges such as long propagation delays, limited onboard computational resources, intermittent connectivity, and growing exposure to cyber threats. In this context, delay-aware encryption scheduling has emerged as an essential approach to ensure secure and efficient data transmission while maintaining quality-of-service requirements. This paper presents a comprehensive review of existing research, focusing on security models, optimization techniques, and emerging computing applications for delay-aware encryption in satellite communication systems. The study systematically analyzes multiple works and categorizes them into key domains, including lightweight cryptographic frameworks, delay-aware scheduling algorithms, optimization-based methods, artificial intelligence-driven approaches, and integrated satellite–terrestrial architectures. It highlights the critical trade-offs between encryption strength, latency, and computational overhead, emphasizing the need for adaptive and scalable solutions. A comparative evaluation is conducted to assess performance across different methodologies in terms of delay efficiency, security robustness, and resource utilization. Furthermore, key challenges such as dynamic network topology, real-time adaptability, energy constraints, and the absence of standardized evaluation frameworks are identified, along with emerging trends like edge computing, quantum-safe encryption, and machine learning-based scheduling for future systems.