IPSeQ: A Security-Enhanced IPSec Protocol Integrated with Quantum Key Distribution

IPSec is a widely used network security protocol that plays a crucial role in providing secure transmission channels in the current Internet. However, the advent of quantum computing poses unprecedented challenges to the security of traditional cryptographic methods, including those used in IPSec. Fortunately, quantum key distribution (QKD) offers a theoretically unbreakable method for exchanging keys between two communicating parties. To address the security threats posed by quantum computing, we propose IPSeQ, a security-enhanced IPSec protocol that integrates QKD into its design. Specifically, IPSeQ leverages quantum keys to strengthen key negotiation, authentication, and data encryption processes. To achieve rapid key updates while ensuring transmission efficiency and key synchronization, IPSeQ introduces a sliding window-based dynamic key updating mechanism. Experiments conducted with real QKD devices demonstrate that our proposed mechanism can improve throughput by more than 50 percent compared to traditional schemes, particularly at higher quantum key generation rates. Additionally, IPSeQ effectively maintains robust data transmission in scenarios where quantum keys are scarce (e.g., when the key generation rate is less than 10 kb/s).