Revisiting Deniability in Quantum Key Exchange

Abstract

We revisit the notion of deniability in quantum key exchange (QKE), a topic that remains largely unexplored. In the only work on this subject by Donald Beaver, it is argued that QKE is not necessarily deniable due to an eavesdropping attack that limits key equivocation. We provide more insight into the nature of this attack and how it extends to other constructions such as QKE obtained from uncloneable encryption. We then adopt the framework for quantum authenticated key exchange, developed by Mosca et al., and extend it to introduce the notion of coercer-deniable QKE, formalized in terms of the indistinguishability of real and fake coercer views. Next, we apply results from a recent work by Arrazola and Scarani on covert quantum communication to establish a connection between covert QKE and deniability. We propose DC-QKE, a simple deniable covert QKE protocol, and prove its deniability via a reduction to the security of covert QKE. Finally, we consider how entanglement distillation can be used to enable information-theoretically deniable protocols for QKE and tasks beyond key exchange. 1 for privacy amplification to get an (n + s)-bit string y ′ . 3: Invert the OTP step to obtain x ′ = y ′ ⊕ e. 4: Parse x ′ as the concatenation m ′ ||µ ′ and use k to verify if MAC(m ′ ) k = µ ′ .

A Privacy Preserving Authentication Protocol Using Quantum Computing for V2I Authentication in Vehicular Ad Hoc Networks

“…e proposed protocol also enables efficient traceability in case a vehicle misbehaves. (3) We have also evaluated the performance of our protocol by implementing it on QKD simulator [35]. e results obtained confirm that it performs reasonably regarding information leakage and key length.…”

“…[45], but the proposed work provides unconditional security, which is not guaranteed by any of the other works. In addition, as the proposed protocol utilizes one of the quantum key distribution protocols, namely, BB84 protocol, we have also evaluated the performance parameters of BB84 protocol by performing simulation in QKD simulator [35]. QKD simulator, which is purely written in Python and applies standard libraries such as Scipy, Numpy, Pycrypto, etc., is well-known for returning simulation results by utilizing QKD stack, which includes a quantum channel, shifting, authentication using hashing, error estimation, error correction, and privacy amplification.…”