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IEEE Transactions on Industrial Electronics

A Novel NTT-based Authentication Scheme for 10 GHz Quantum Key Distribution Systems

Baokang Zhao, Bo Liu, Chunqing Wu, Wanrong Yu, Jinshu Su, Ilsun You, Francesco Palmieri

Published Jan 1, 2016• 17 citations
Publisher

Abstract

The quantum key distribution (QKD) technology is achieving a growing interest in both the scientific and industrial communities. Based on principles of quantum mechanics, it can provide unconditional security in key exchanges over end-to-end communication channels. Information-theoretically secure (ITS) authentication, the compulsory procedure of QKD systems, avoids the man-in-the-middle attack during the security key generation. In this paper, we propose a novel family of almost strongly universal (ASU) hash functions based on number-theoretic transforms (N-ASU), and prove that N-ASU hash functions can meet the high security requirement of an ITS authentication procedure. With such N-ASU hash functions, we propose a novel efficient NTT-based authentication algorithm (N-Auth) for QKD systems. Such a solution offers nearly the same security guarantees provided by the available authentication algorithms built upon ASU hash functions, but is characterized by a much lower computational complexity. The experimental results show that the N-Auth algorithm can fully meet the real-time and high-performance demands of modern 10-GHz QKD systems, making it a viable solution for the implementation of industrial-strength unconditionally secure broadband communication solutions.

DOI
10.1109/tie.2016.2552152

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The quantum key distribution (QKD) technology is achieving a growing interest in both the scientific and industrial communities. Based on principles of quantum mechanics, it can provide unconditional security in key exchanges over end-to-end communication channels. Information-theoretically secure (ITS) authentication, the compulsory procedure of QKD systems, avoids the man-in-the-middle attack during the security key generation. In this paper, we propose a novel family of almost strongly universal (ASU) hash functions based on number-theoretic transforms (N-ASU), and prove that N-ASU hash functions can meet the high security requirement of an ITS authentication procedure. With such N-ASU hash functions, we propose a novel efficient NTT-based authentication algorithm (N-Auth) for QKD systems. Such a solution offers nearly the same security guarantees provided by the available authentication algorithms built upon ASU hash functions, but is characterized by a much lower computational complexity. The experimental results show that the N-Auth algorithm can fully meet the real-time and high-performance demands of modern 10-GHz QKD systems, making it a viable solution for the implementation of industrial-strength unconditionally secure broadband communication solutions.
Quantum Key Distribution (QKD) is a secret key agreement technique that consists of two parts: quantum transmission and measurement on a quantum channel, and classical post-processing on a public communication channel. It enjoys provable unconditional security provided that the public communication channel is immutable. Otherwise, QKD is vulnerable to a man-in-the-middle attack. Immutable public communication channels, however, do not exist in practice. So we need to use authentication that implements the properties of an immutable channel as well as possible. One scheme that serves this purpose well is the Wegman-Carter authentication (WCA), which is built upon Almost Strongly Universal2 (ASU2) hashing. This scheme uses a new key in each authentication attempt to select a hash function from an ASU2 family, which is then used to generate the authentication tag for a message. The main focus of this dissertation is on authentication in the context of QKD. We study ASU2 hash functions, security of QKD that employs a computationally secure authentication, and also security of authentication with a partially known key. Specifically, we study the following. First, Universal hash functions and their constructions are reviewed, and as well as a new construction of ASU2 hash functions is presented. Second, security of QKD that employs a specific computationally secure authentication is studied. We present detailed attacks on various practical implementations of QKD that employs this authentication. We also provide countermeasures and prove necessary and sufficient conditions for upgrading the security of the authentication to the level of unconditional security. Third, Universal hash function based multiple authentication is studied. This uses a fixed ASU2 hash function followed by one-time pad encryption, to keep the hash function secret. We show that the one-time pad is necessary in every round for the authentication to be unconditionally secure. Lastly, we study security of the WCA scheme, in the case of a partially known authentication key. Here we prove tight information-theoretic security bounds and also analyse security using witness indistinguishability as used in the Universal Composability framework.
Abstract In addition to the quantum channel, an auxiliary classical authentic communication channel is required for quantum key distribution. To provide unconditional security in quantum cryptography, which based on the fundamental laws of quantum mechanics, information-theoretic authentication is required, and not authentication based on computational complexity. The paper provides a security proof of information-theoretic authentication in quantum cryptography using ɛ -ASU 2 hash functions. The internal structure of ɛ -ASU 2 hash functions is not used in the proof, so these hash functions can be implemented by a different composition of other hash functions, for example, including the composition ɛ -AXU 2 functions with a reused key and subsequent encryption of the tag with a one-time pad key, which is taken from the previous session of quantum key distribution. It is also shown that information-theoretic authentication preserves composable security of the keys. This authentication method can also be used for key agrrement in in networks with trusted nodes (Molotkov 2022 Laser Phys. Lett. 19 045201–9; Arbekov and Molotkov 2020 Laser Phys. Lett. 17 055202–8) and with quantum key distribution.
In this article, we investigate the issue of authenticating the classical post-processing components of a QKD protocol through an insecure channel. Our analysis starts with state-of-the-art solutions and subsequently introduces an authentication scheme aiming at both Information Theoretic Security and resiliency from particular denial-of-service attacks targeting the authentication procedure. The proposed strategy combines -Almost Strongly Universal hashing for unconditional protection and computationally-secure Message Authentication Codes for DoS detection capability. Specifically, we consider the protocol security in a typical QKD scenario, taking into account partially weak authentication keys. Moreover, we add practical considerations related to authentication parameters and experimentally evaluate the performance of the proposed system in terms of computational complexity and key consumption in a reasonable use case.
Quantum Key Distribution (QKD - also referred to as Quantum Cryptography) is a technique for secret key agreement. It has been shown that QKD rigged with Information-Theoretic Secure (ITS) authentication (using secret key) of the classical messages transmitted during the key distribution protocol is also ITS. Note, QKD without any authentication can trivially be broken by man-in-the-middle attacks. Here, we study an authentication method that was originally proposed because of its low key consumption; a two-step authentication that uses a publicly known hash function, followed by a secret strongly universal2 hash function, which is exchanged each round. This two-step authentication is not information-theoretically secure but it was argued that nevertheless it does not compromise the security of QKD. In the current contribution we study intrinsic weaknesses of this approach under the common assumption that the QKD adversary has access to unlimited resources including quantum memories. We consider one implementation of Quantum Cryptographic protocols that use such authentication and demonstrate an attack that fully extract the secret key. Even including the final key from the protocol in the authentication does not rule out the possibility of these attacks. To rectify the situation, we propose a countermeasure that, while not information-theoretically secure, restores the need for very large computing power for the attack to work. Finally, we specify conditions that must be satisfied by the two-step authentication in order to restore information-theoretic security.
The promise of unconditional security in the Quantum Key Distribution (QKD) depends on the availability of an authenticated classical channel. However, practical implementations often overlook this requirement or rely on computational assumptions that compromise long-term security. To overcome these challenges, this paper presents Entanglement-Based Authenticated Quantum Key Distribution (EAQKD), a novel protocol that addresses critical security and practical limitations in quantum cryptographic key exchange. Our approach integrates quantum entanglement distribution with information-theoretic authentication. We evaluate EAQKD's performance through a comprehensive discrete-event simulation framework modeled on realistic channel characteristics and experimental device parameters. Our modeling incorporates parameters from practical quantum optics setups, including SPDC entanglement sources, superconducting nanowire detectors, and fiber channel imperfections. Our results show quantum bit error rates consistently below the 11% security threshold (ranging from 1.86% at 10 km to 9.27% at 200 km), with secure key rates achieving 1.12×1051.12 \times 10^51.12×105 bits/s at short distances and maintaining practical rates of 9.8 bits/s at 200 km. When integrated with quantum repeater architectures, our analysis projects that EAQKD can extend secure communication beyond 500 km while providing information-theoretic security guarantees. Comparative analysis against the BB84, E91, and Twin-Field QKD protocols demonstrates EAQKD's superior balance of security, practical performance, and implementation robustness. This work advances quantum cryptography by providing a rigorously analyzed engineering reference for secure key distribution in future quantum communication networks.
Quantum Key Distribution (QKD) protocols require Information-Theoretically Secure (ITS) authentication of the classical channel to preserve the unconditional security of the distilled key. Standard ITS schemes are based on one-time keys: once a key is used to authenticate a message, it must be discarded. Since QKD requires mutual authentication, two independent one-time keys are typically consumed per round, imposing a non-trivial overhead on the net secure key rate. In this work, we present the authentication-with-response scheme, a novel ITS authentication scheme based on ε\varepsilonε-Almost Strongly Universal2_22​ (ε\varepsilonε-ASU2_22​) functions, whose IT security can be established in the Universal Composability (UC) framework. The scheme achieves mutual authentication consuming a single one-time key per QKD round, halving key consumption compared to the state-of-the-art.