The existence of a quantum computer is one of the most significant threats cryptography has ever faced. However, it seems that real world protocols received little attention so far with respect to their future security. Indeed merely relying upon post-quantum primitives may not suffice in order for a security protocol to be resistant in a full quantum world. In this paper, we consider the fundamental UMTS key agreement used in 3G but also in 4G (LTE), and in the (recently deployed) 5G technology. We analyze the protocol in a quantum setting, with quantum communications (allowing superposition queries by the involved parties), and where quantum computation is granted to the adversary. We prove that, assuming the underlying symmetric-key primitive is quantum-secure, the UMTS key agreement is also quantum-secure. We also give a quantum security analysis of the underlying primitives, namely Milenage and TUAK. To the best of our knowledge this paper provides the first rigorous proof of the UMTS key agreement in a strong quantum setting. Our result shows that in the quantum world to come, the UMTS technology remains a valid scheme in order to secure the communications of billions of users.
The existence of a quantum computer is one of the most significant threats cryptography has ever faced. However, it seems that real world protocols received little attention so far with respect to their future security. Indeed merely relying upon post-quantum primitives may not suffice in order for a security protocol to be resistant in a full quantum world. In this paper, we consider the fundamental UMTS key agreement used in 3G but also in 4G (LTE), and in the (recently deployed) 5G technology. We analyze the protocol in a quantum setting, with quantum communications (allowing superposition queries by the involved parties), and where quantum computation is granted to the adversary. We prove that, assuming the underlying symmetric-key primitive is quantum-secure, the UMTS key agreement is also quantum-secure. We also give a quantum security analysis of the underlying primitives, namely Milenage and TUAK. To the best of our knowledge this paper provides the first rigorous proof of the UMTS key agreement in a strong quantum setting. Our result shows that in the quantum world to come, the UMTS technology remains a valid scheme in order to secure the communications of billions of users.
For modern cryptography, the security of a system is defined as the sum of the resources required to break it. With the advent of efficient quantum computers and the new algorithmic possibilities that this opens, this amount of resource is destined to change.In this thesis, we take a step towards a better understanding of this quantum threat. After an introduction to quantum computation and cryptography, we show quantum attacks against the Legendre PRF in the setting without superposition queries and reduced quantum memory. Afterwards, we present a general way to transpose boomerang attacks into quantum attacks as well as some applications. We continue on a doubling method for block ciphers inspired by the Encrypt-Mix-Encrypt scheme and prove its security. We end by building a quantum version of the 3G/4G/5G UMTS-AKA authentication protocol before showing the security as well as the underlying primitives Milenage and TUAK.
The current 5G-AKA protocol faces significant security challenges, including the lack of Perfect Forward Secrecy and Post-Quantum (PQ) security. In particular, the absence of PQ protection makes current communications vulnerable to future quantum adversaries who may decrypt stored messages once large-scale quantum computers become available. To mitigate this risk, a transition to PQ security must be implemented as soon as possible. Two primary approaches exist for this transition: (1) symmetric key-based techniques, which require a secure channel for key distribution, leading to increased costs, and (2) modern PQ public-key primitives, which offer stronger security but come with high communication overhead. In this paper, we propose a solution that leverages PQ cryptographic primitives for confidentiality and privacy protection, while retaining classical public-key cryptography for authentication. This approach is viable because digital signatures must be secure today, even if they are compromised in the future. Moreover, our framework allows for a seamless transition to fully PQ-secure authentication when quantum threats become imminent. In addition, the framework also supports the zero-trust architecture in which no secure channel between Serving Network (SN) and Home Network (HN) is assumed. We have carefully analysed the security of the proposed protocol using both informal and formal (Real-Or-Random (ROR) logic and Scyther Validation tool) methods. We also compared its performance in terms of computation, communication, and storage, and found that it performs better than existing protocols.
5G communication enables digital innovation by integrating a wide range of services, making security, especially primary authentication, critically important. To secure 5G communication, the 3GPP has designed the 5G Authentication and Key Agreement (5G-AKA) protocol. However, current trends show a growing interest in post-quantum security, and 5G-AKA is not resistant to quantum-era threats due to several classical vulnerabilities. To address these limitations, various enhanced versions of 5G-AKA have been proposed, claiming to provide security against attacks that exploit its weaknesses. However, state-of-the-art research reveals that many of these versions remain susceptible to classical threats, such as attacks from malicious serving networks (SNs), ephemeral secret leakage (ESL) attacks, and fail to provide perfect forward secrecy. Additionally, they are not secure against quantum attacks. In response to these challenges, we propose a Post-Quantum Secure, Lattice-Based 5G-AKA Protocol that is resistant to malicious serving networks and ensures perfect forward secrecy. Our proposed protocol is built on lattice-based cryptography, making it one of the first 5G-AKA variants designed with post-quantum security in mind. We validate the security of our protocol using formal verification techniques, including the Real-Or-Random (ROR) model and the Scyther tool. Furthermore, we perform a comparative analysis with existing protocols to highlight the improvements. Finally, we implement our protocol in a testbed environment to demonstrate its practical feasibility for real-time 5G applications.
With the rapid advancement of quantum computing, existing cryptographic schemes in 4G LTE and 5G networks confront serious security threats. Traditional reliance on protocols like IPsec and Transport Layer Security leaves infrastructure vulnerable to future quantum attacks, particularly “Harvest Now, Decrypt Later” attacks, where adversaries store current encrypted traffic for future decryption. To counter these threats, Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD) have become potential solutions. As future 6G networks aim to realize ultra-reliable and ubiquitous secure connectivity, it is essential to incorporate both PQC and QKD solutions to ensure long-term robustness. Therefore, the synergy of these security solutions and 5G draws the attention of researchers and practitioners worldwide. This study systematically reviews the literature in this specific field. We analyzed evidence from reviewed literature to address three research questions, resulting in a novel taxonomy to categorize publications in this area and a vision for a quantum-safe 6G network. Moreover, we discussed several open challenges in 5G, PQC, and QKD, along with future work.
Millions of devices are becoming part of Internet of Things/5G. Securing these devices against all potential threats is a huge challenge. The 5G specification goals require rigid and robust security protocol against such threats. Quantum cryptography is a recently emerged term in which we test the robustness of security protocols against quantum computers. Therefore, in this article, we propose a security protocol called quantum key GRID for authentication and key agreement (QKG-AKA) scheme for the dynamic security association. This scheme is efficiently deployed in long term evolution architecture without any significant modifications in the underlying base system. The proposed QKG-AKA mechanism is analyzed for robustness and proven safe against quantum computers. The simulation results and performance analysis show drastic improvement regarding security and key management over existing schemes.
Advancements in 5G are largely driven by its adoption across a variety of applications, including smart homes, smart healthcare, autonomous vehicles, transportation, and Industry 5.0. However, this widespread usage raises significant security and privacy concerns, particularly regarding authentication. To secure 5G communications, 3GPP has standardised the 5G-Authentication and Key Agreement (5G-AKA) protocol. Despite this, state-of-the-art research has revealed that 5G-AKA suffers from several vulnerabilities. In response, numerous alternative authentication schemes have been proposed. Nevertheless, many of these protocols continue to be susceptible to classical security threats, such as malicious serving network (SN) attacks, ephemeral secret leakage, traceability, anonymity violations, and, most critically, a lack of Perfect Forward Secrecy (PFS). Additionally, recent advancements in quantum computing pose a substantial risk to the security of 5G-AKA and its variants, rendering them insecure in the post-quantum era. Although a few post-quantum cryptography-based protocols have been introduced, studies show that they are either computationally expensive or still vulnerable to quantum attacks. In order to tackle these challenges, we propose two versions of a novel authentication protocol that not only provide comprehensive security guarantees but are also computationally efficient. Version 1 utilises a hybrid cryptographic approach (AES + KEM) and achieves the lowest computational cost—even lower than Version 2, which relies solely on KEM. Both versions offer the same level of security, but Version 1 is significantly more efficient in terms of resource usage. We have validated our proposed protocols using the Real-Or-Random (ROR) model and the Scyther tool. Furthermore, we evaluated their performance against existing protocols under both known and unknown attack scenarios. The results show that our protocols incur lower computational, communication, and energy overhead, as well as strong resilience against unknown attacks, outperforming several existing authentication schemes. Furthermore, we implement a testbed to demonstrate the real-time applicability of both proposed versions.