The Quantum Key Distribution (QKD) protocol utilizes quantum mechanics principles for cryptographic key exchange, ensuring absolute secrecy. Current QKD techniques are susceptible to man-in-the-middle (MITM) attacks due to the absence of an inherent mechanism for identity verification within the quantum channel. For authentication, these systems rely on classical or post-quantum cryptography, which diminishes the perfect security advantage provided by QKD. We present a Physical Unclonable Function (PUF)-based authenticated QKD protocol (PUF-AQKD), which avoids the necessity for authenticated classical channels and is useful in mitigating MITM attacks. The fundamental concept of PUF-AQKD is to implement a phase shift in the basis used for polarizing the transmitted qubits. The phase shift is dictated by PUFs, which are anticipated to result in analogous (correlated) responses for devices manufactured under similar conditions but dissimilar responses in different conditions. An adversary lacking a correlated PUF response shared by Alice and Bob would inadvertently increase the Quantum Bit Error Rates (QBER) observed at Bob’s end. We present a mathematical model to assess the efficacy of the proposed PUF-AQKD method and perform simulations utilizing the NetSquid simulator. The mathematical analysis and simulation findings indicate that PUF-AQKD can efficiently identify eavesdroppers, even during incomplete measurements, without the necessity of an authorized classical channel.
The Quantum Key Distribution (QKD) protocol utilizes quantum mechanics principles for cryptographic key exchange, ensuring absolute secrecy. Current QKD techniques are susceptible to man-in-the-middle (MITM) attacks due to the absence of an inherent mechanism for identity verification within the quantum channel. For authentication, these systems rely on classical or post-quantum cryptography, which diminishes the perfect security advantage provided by QKD. We present a Physical Unclonable Function (PUF)-based authenticated QKD protocol (PUF-AQKD), which avoids the necessity for authenticated classical channels and is useful in mitigating MITM attacks. The fundamental concept of PUF-AQKD is to implement a phase shift in the basis used for polarizing the transmitted qubits. The phase shift is dictated by PUFs, which are anticipated to result in analogous (correlated) responses for devices manufactured under similar conditions but dissimilar responses in different conditions. An adversary lacking a correlated PUF response shared by Alice and Bob would inadvertently increase the Quantum Bit Error Rates (QBER) observed at Bob’s end. We present a mathematical model to assess the efficacy of the proposed PUF-AQKD method and perform simulations utilizing the NetSquid simulator. The mathematical analysis and simulation findings indicate that PUF-AQKD can efficiently identify eavesdroppers, even during incomplete measurements, without the necessity of an authorized classical channel.
The rapid advances in quantum computing pressure the existing essential cryptographic algorithms. In this context, Quantum Key Distribution (QKD) has been proposed as a quantum safe solution for key distribution. However, current QKD systems require an authenticated classical channel which relies on pre-shared symmetric keys that are manually distributed and do not guarantee the identity of the hardware that hosts them. This paper proposes a novel scheme, the Physically Unclonable Quantum Key Distribution (PU-QKD) system, to intrinsically authenticate the communicating endpoints in QKD. The PU-QKD scheme leverages classical Physical Unclonable Functions (PUFs) to encode the data transmission in discrete variable QKD protocols (e.g., BB84). Our scheme maintains the information-theoretic security of QKD protocols by integrating the PUF as an additional layer. Authentication is bound to hardware, providing a robust fingerprint, while lower post-processing overhead increases key rates. Additionally, the proposed scheme is resilient against state-of-the-art PUF vulnerabilities, such as modeling attacks.
With the increase of digital devices, the need for robust authentication mechanisms has become crucial. Traditional methods relying on cryptographic key management are susceptible to various risks, particularly the exposure of keys to interception or theft. As cyber threats evolve, the short-comings of these methods are accentuated, necessitating more secure solutions. Physically Unclonable Functions (PUFs) have emerged as a potential alternative, utilizing inherent hardware variations for device authentication without stored secrets. However, recent studies reveal vulnerabilities in conventional PUF implementations. Simultaneously, there's a growing recognition for authentication mechanisms tailored for quantum devices. This recognition has prompted the exploration of Quantum PUFs (QPUFs), which represent a promising solution to enhance security and reliability, leveraging the unique properties of quantum mechanics. In this paper, we propose a novel approach using QPUFs for device authentication that does not require any quantum communication channel or even quantum memory. We design a quantum circuit to serve as a QPUF, evaluating metrics such as instability, randomness, and uniqueness. Additionally, we devise an authentication scheme that exploits the challenge-response paradigm, taking advantage of the distinctive properties of quantum PUFs. Furthermore, we delineate a threat model to identify and mitigate potential risks associated with the authentication process. By assessing the proposed QPUFs efficacy on real real quantum hardware provided by IBM, this research contributes to the advancement of secure authentication protocols in quantum era.
This paper proposes a novel protocol for authenticated quantum key distribution (QKD) that addresses the inherent vulnerabilities of traditional, centralized key management systems. The core concept leverages the security of QKD to establish a shared secret key, then integrates this key with a classical authentication protocol to verify the identities of the communicating parties. The protocol, denoted as AQKD, aims to enhance overall communication security by combining the unique properties of quantum key distribution with robust classical authentication mechanisms. The design incorporates a multi-round key exchange utilizing Bennett-May-Crabtree (BMC) protocol and incorporates a challenge-response mechanism for authentication. The proposed protocol mitigates risks associated with compromised central servers and provides a more resilient security posture. The primary contribution lies in the synergistic integration of these two established cryptographic paradigms, resulting in a more secure and adaptable communication system. The protocol's security is analyzed, considering potential attacks and demonstrating its resilience. The simulation results highlight the effectiveness of AQKD in establishing secure communication channels, particularly against eavesdropping and identity forgery attempts.
Quantum Key Distribution (QKD) enables Information-Theoretically Secure (ITS) key exchange, robust even against future quantum computing threats. However, a fundamental limitation of QKD is the requirement for an authenticated classical channel, which necessitates a pre-shared secret key. In this work, we address this challenge by adopting a Hybrid Entangled Physical Unclonable Function (PUF) protocol for authentication. We demonstrate that this PUF-based method generates an ITS initial key under minimal explicit hardware assumptions. This approach allows us to experimentally perform a fully ITS-authenticated entanglement-based QKD protocol that relies solely on such assumptions, effectively eliminating the need for pre-shared secrets. This represents a significant step towards the practical realization of quantum network protocols using lightweight, readily available hardware assumptions, without weakening security guarantees.
Quantum key distribution (QKD) is a method using some properties of quantum mechanics to create a secret shared cryptographic key even if an eavesdropper has access to unlimited computational power. All QKD protocols require that the parties have access to an authentic channel. Otherwise, QKD is vulnerable to man-in-the-middle attacks. This paper studies QKD from this point of view, emphasizing the necessity and sufficiency of using unconditionally secure authentication in QKD. In this work, a new technique of using unconditionally secure authentication is proposed for quantum cryptosystems. This technique is based on a hybrid of normal application of authentication codes and the so-called “counter-based” authentication method such that to achieve a better trade-off between security and efficiency (in terms of the required size of initially shared secret data). Based on this strategy, an authenticated version of a typical QKD protocol (the well-known BB84 protocol) is described. Some advantages of our protocol in comparison to other proposals are also highlighted.
As quantum technologies advance, ensuring secure authentication of quantum devices has become increasingly important. Existing methods, often relying on stored cryptographic keys, are vulnerable to physical and side-channel attacks. Quantum Physical Unclonable Functions (QPUFs) offer a promising alternative by leveraging quantum phenomena such as superposition, entanglement, and quantum noise to produce unique, unclonable responses. However, many existing QPUF designs are based on simulations or report only idealized, best-case results. This work presents and evaluates a set of QPUF circuits on IBM’s real quantum hardware, assessing their performance in terms of instability, randomness, and uniqueness to identify the most effective configurations. Our results show that specific configurations can achieve a positive balance between stability and device distinguishability, reaching 0.05 instability, 0.48 uniqueness, and 0.75 randomness. These findings provide a solid foundation for implementing robust authentication protocols tailored for quantum devices in real-world settings.