SDSE stream encryption protocol: data protection in fiber-optic networks with cryptographic strength comparable to quantum protocols

Abstract

This paper presents a comparative analysis of three cryptographic approaches to securing fiber-optic data transmission: classical RSA/AES, Quantum Key Distribution (QKD) based on the E91 protocol, and Secure Dynamic Stream Encryption (SDSE). These are evaluated in terms of latency, key renewal frequency, computational load, energy efficiency, and resilience to quantum attacks. In addition to these core comparisons, we extend SDSE with a blockchain-based governance layer. This enhancement introduces auditable key management through distributed ledger technology (DLT), ensuring transparent tracking of key rotations, revocations, and policy enforcement without storing any secret material. The blockchain acts as a trust anchor for multi-node synchronization, particularly useful in federated or multi-domain environments. The combined SDSE + Blockchain framework provides a lightweight, quantum-resilient, and scalable encryption mechanism suitable for real-world deployment across conventional optical infrastructure.