Recent advancements in secure communication systems require the establishment of an end-to-end secure, decentralized, and efficient key management system. Implementing key management methods on time-sensitive technologies, specifically designed for Voice over Internet Protocol (VoIP), is inherently complicated. This paper presents a novel decentralized key agreement scheme for secure Voice over Internet Protocol (VoIP) communication, combining the blockchain-based user data management with Echo State Network driven pseudo random number generator (ESN-driven PRNG) within a peer-to-peer Session Initiation Protocol (P2P SIP) architecture. The combination of blockchain enabled user data management and P2P SIP model eliminates reliance on centralized system elements, such as SIP server, and improves the system availability and security. An ESN-driven PRNG provides unpredictable and high-entropy keys and random numbers with low computational complexity, thereby enhancing security and resistance to predictive attacks, especially in real-time and resource-constrained environments. Empirical evaluation demonstrates that the ESN-PRNG achieves a Shannon entropy of 0.999992 bits/bit and passes all four NIST (National Institute of Standards and Technology of U.S.) SP 800–22 statistical randomness tests (4/4), confirming its cryptographic suitability. We demonstrate the security robustness of our proposed model via formal and informal analysis. The simulation-based experimental results indicate that the decentralized design of the proposed model remarkably improves the availability and performance. We also compared performance and security results of our study with recent studies in literature. Results show that our model outperforms existing key agreement techniques by up to 36.0%, while improving security and availability.
ŞANLIÖZ et al. (Thu,) studied this question.