Multipath Authentication without Shared Secrets and With Applications in Quantum Networks

Naomi R. Solomons, Siddarth Koduru Joshi

Ronny Döring, Marc Geitz

This paper proposes and evaluates multiple imple-mentations designed to fortify the security and resilience of a key exchange platform. Leveraging Shamir's Secret Sharing tech-nique, the system generates N sub-messages transmitted through disjoint network paths, preventing classical and quantum-enabled adversaries from reconstructing the original message without access to the requisite K sub-messages. Additionally, the inte-gration of Post-Quantum Cryptography, both before and after applying Shamir's Secret Sharing, employing Key Encapsulation Mechanisms for message encryption and signature algorithms for authentication, bolsters the platform's resilience against attacks on multiple networks. Successful attacks on either the Post-Quantum Cryptography or Shamir's Secret Sharing components in our implementation would not compromise the overall system security due to the two-factor approach. Experimental results demonstrate the effectiveness of the implemented system, achieving proficient key exchange rates under typical network traffic loads.

Yu‐Guang Yang, Qiaoyan Wen, Xing Zhang

Varshinee Krishnamurthy, Ranjiny Natarajan Kumar, Sivasankar Sundaram

A less expensive and more flexible solution to the problem of sharing secret keys between wireless nodes is to use the inherent randomness in the wireless channel between them as the source for extracting bits of the secret key between these nodes. We propose a new secret key distribution approach that utilizes the uniformly distributed phase information of channel responses to extract shared cryptographic keys under narrowband multipath fading models. Compared to existing approaches which only support pair wise key distribution, our scheme is highly scalable and can support efficient group key distribution. Various key distribution schemes are appraised to determine the level of security and connectivity. Simulated results show that key distribution exploiting channel phase has improved resilience against node capture. them as the source for extracting bits of the secret key between these nodes. Shared secret key distribution from channel measurements is an application which benefits from the randomnessof the multipath channel. It would not, for example, work in a truly free-space environment (such as deep space radio links). Secret sharing benefits from: • Reciprocity of the wireless radio channel: The multipath properties of the radio channel (gains, phase shifts, and delays) at any point in time and on any given frequency channel are identical on both directions of the link. • Temporal variations in the radio channel: Over time, the multipath channel changes due to movement of either end of the link, and any motion of people and objects in the environment near the link. An application may specifically request a user to move or shake the wireless device in order to generate more temporal variation. • Spatial variations: The properties of the radio channel are unique to the locations of the two endpoints of the link. An eavesdropper at a third location more than a few wavelengths from either endpoint will measure a different, uncorrelated radio channel. The proposed scheme is more flexible and can be applied in both static and mobile environments. Our scheme introduces phase randomness to bit distribution and removes the reliance on node mobility to obtain high entropy bits. We evaluate the proposed schemes through both analytical and simulation studies. The parameters of the scheme can be selected such that a desired level of key distribution accuracy and reliability is achieved with high efficiency.

Wai Ming Chan, Rémi A. Chou, Taejoon Kim

This paper introduces the first two-dimensional XOR-based secret sharing scheme for layered multipath communication networks. We present a construction that guarantees successful message recovery and perfect privacy when an adversary observes and disrupts any single path at each transmission layer. The scheme achieves information-theoretic security using only bitwise XOR operations with linear O(|S|) complexity, where |S| is the message length. We provide mathematical proofs demonstrating that the scheme maintains unconditional security regardless of computational resources available to adversaries. Unlike encryption-based approaches vulnerable to quantum computing advances, our construction offers provable security suitable for resource-constrained military environments where computational assumptions may fail.