Moving target defense (MTD) strategies have been widely studied for securing computer communication systems. We consider using MTD strategies as a cryptographic mechanism for providing secure communication when the adversary has access to a quantum computer and security is required over a long period of time. We assume Alice and Bob are connected by multiple disjoint paths, not all of which can be eavesdropped by the attacker at the same time. We propose a cryptographic system that uses an MTD strategy that achieves long-term quantum-safe security. We model the system as a Markov chain, and propose two security measures that correspond to two types of adversaries, called risk-taking and risk-averse. Our numerical simulations shows dependencies between system parameters, and leads to new insights, such as quantifying the cost of being a risk-averse adversary.
Moving target defense (MTD) strategies have been widely studied for securing computer communication systems. We consider using MTD strategies as a cryptographic mechanism for providing secure communication when the adversary has access to a quantum computer and security is required over a long period of time. We assume Alice and Bob are connected by multiple disjoint paths, not all of which can be eavesdropped by the attacker at the same time. We propose a cryptographic system that uses an MTD strategy that achieves long-term quantum-safe security. We model the system as a Markov chain, and propose two security measures that correspond to two types of adversaries, called risk-taking and risk-averse. Our numerical simulations shows dependencies between system parameters, and leads to new insights, such as quantifying the cost of being a risk-averse adversary.
Moving target defense (MTD) strategies have been widely studied for securing computer systems. We consider using MTD strategies to provide long-term cryptographic security for message transmission against an eavesdropping adversary who has access to a quantum computer. In such a setting, today’s widely used cryptographic systems including Diffie-Hellman key agreement protocol and RSA cryptosystem will be insecure and alternative solutions are needed. We will use a physical assumption, existence of multiple communication paths between the sender and the receiver, as the basis of security, and propose a cryptographic system that uses this assumption and an MTD strategy to guarantee efficient long-term information theoretic security even when only a single path is not eavesdropped. Following the approach of Maleki et al., we model the system using a Markov chain, derive its transition probabilities, propose two security measures, and prove results that show how to calculate these measures using transition probabilities. We define two types of attackers that we call risk-taking and risk-averse and compute our proposed measures for the two types of adversaries for a concrete MTD strategy. We will use numerical analysis to study tradeoffs between system parameters, discuss our results, and propose directions for future research.
Quantum computing's quick growth brings chances and risks to defense communication systems. Current methods that protect military networks could be at risk from quantum attacks, making new privacy systems necessary. This article looks into adding quantum tech like quantum key distribution, post-quantum crypto, and mixed security setups to make defense communications more secure. Using quantum mechanics, these systems can offer secure key exchange and protection from spying. The article studies ways to add quantum-safe methods to military communication, looks at possible performance problems, and talks about how to use them in defense. The results show that a layered approach, using quantum crypto with security methods, can greatly improve security in crucial communication channels. This work helps create secure communication systems that can stand against both types of attacks.
Abstract—Quantum networks are communication networks in which adjacent nodes enjoy perfectly secure channels thanks to quantum key distribution (QKD). While QKD is renowned for perfect point-to-point security and its eavesdropping detec-tion capabilities, end-to-end security is nontrivial to achieve. More importantly, the eavesdropping detection can indeed be turned against the system itself. It is known that perfect end-to-end security can be created from point-to-point security by means of multipath transmission (in fact, there is no other way to do this, assuming no pre-shared secrets and avoiding public-key cryptography). However, multipath transmission requires node-disjoint paths, which in turn are to be assured by the underlying routing protocol. At this point, an active or passive adversary may intentionally eavesdrop on the QKD protocol to temporarily cut a channel and to cause key-buffers running empty and enforcing local rerouting of packets towards nodes under his control. Consequently, the multipath transmission channels might no longer be non-intersecting, thus defeating the overall security by exploiting QKD’s eavesdropping detec-tion facilities. Alternatively, an active adversary may as well insert bogus traff c to cause local congestion, thus even sparing the effort of eavesdropping on a QKD link. In this work, we use Markov chains to model a multipath transmission, and we discuss the extent to which secure multipath transmission is resilient against local congestions caused by an adversary. We argue that a protection against an active adversary who uses bogus traff c to f ddle with the routing, calls for additional security measures, perhaps even beyond the capabilities of QKD or multipath transmission. It turns out that robustness against passive and active adversaries can be retained as long as no bogus traff c is observed.
The rapid advancement of quantum computing poses a significant threat to the confidentiality and integrity of classified and defense communications. Quantum algorithms have the potential to undermine widely deployed public key cryptographic schemes, exposing sensitive military and governmental information to interception and decryption. Foundational work in quantum cryptography has demonstrated that the principles of quantum mechanics can be leveraged to achieve fundamentally secure key distribution, offering a promising countermeasure to quantum-enabled attacks (Bennett & Brassard, 2014; Ekert, 1991). As defense communication systems increasingly rely on longterm data confidentiality, the urgency of transitioning toward quantum-resilient security architectures has become a strategic priority. Despite their widespread adoption, classical cryptographic mechanisms are increasingly vulnerable in the post-quantum era. Studies on post-quantum cryptography have shown that many conventional encryption and key exchange algorithms are susceptible to quantum adversaries, necessitating the development and standardization of new cryptographic primitives (Chen et al., 2016). Ongoing standardization efforts further highlight the complexity of migrating large-scale, mission-critical systems to quantum-safe solutions, particularly within defense environments where interoperability, reliability, and assurance requirements are stringent (Alagic et al., 2025). In parallel, artificial intelligence has emerged as a powerful enabler of advanced security analytics. Machine learning and deep learning techniques enhance intrusion detection, anomaly identification, and adaptive response capabilities within complex communication infrastructures (Buczak & Guven, 2016). Recent research also demonstrates that AI can be applied directly within quantum cryptographic systems, for example by improving signal processing, error correction, and performance optimization in quantum key distribution implementations (Chin et al., 2021). The convergence of quantum cryptography and AIdriven analytics therefore offers a complementary and proactive approach to securing defense communications against both classical and quantum threats. This paper analyzes the integration of quantum cryptography and artificial intelligence as a unified framework for protecting classified and defense communications. It synthesizes advances in quantum key distribution, post-quantum cryptography, and AI-based security analytics, and proposes an integrated perspective that enhances resilience, detection capability, and operational robustness. The study highlights key implications for defense communication systems, emphasizing how AI-enhanced quantum security architectures can support long-term confidentiality, adaptive defense, and strategic cyber resilience in the evolving threat landscape (Sarker et al., 2021).
Quantum computing represents a fundamental shift in computational capability, using quantum mechanical principles, such as superposition, entanglement, and interference, in order to process information exponentially faster than classical systems. Unlike traditional computers that manipulate bits as 0s and 1s, quantum computers harness qubits that exist in probabilistic superposition states, enabling exploration of multiple solutions at the same time. While this advancement promises transformative applications in molecular modeling, optimization, and machine learning, it also threatens the cryptographic foundations securing modern digital infrastructure. The security of modern-day systems relies on mathematical problems that are not easily solvable for classical computers. Quantum algorithms, particularly Shor’s Algorithm and Grover’s Algorithm, render current asymmetric and symmetric encryption protocols computationally vulnerable; critically, the “Harvest Now, Decrypt Later” strategy transforms present-day communications into long-term security liabilities affecting government, financial, healthcare, and critical infrastructure sectors. To address this threat, this paper evaluates post-quantum cryptographic defenses and proposes Quantum Key Distribution (QKD) as the optimal security framework. Unlike mathematical approaches vulnerable to algorithmic advances, QKD anchors security in the No-Cloning theorem and wave-function collapse, ensuring that eavesdropping attempts introduce detectable anomalies, enabling real-time threat detection. Through comparative analysis of scalability, deployment feasibility, and cost efficiency, this paper demonstrates that QKD provides the most robust, future-proof mechanism for protecting sensitive data transmission in the quantum era, offering a critical blueprint for resilient network defense against emerging computational threats.