Modern networks generate high-dimensional traffic that requires numerous features for effective intrusion detection and cybercrime defence, creating a critical challenge for quantum approaches, where qubit availability remains the primary bottleneck for near-term implementation. We present a quantum-enhanced framework that employs Dual-Parameter encoding, using both the polar angle θ and azimuthal phase ϕ of each qubit to encode two normalized features, combined with multi-metric anomaly scoring and calibrated false-positive control. Our detector forms a composite score [Formula: see text] that unifies quantum fidelity (global state similarity), Kullback-Leibler divergence (distributional shift), and von Neumann entropy change (uncertainty shift). The decision threshold is set by quantile calibration on benign validation, and via the Dvoretzky-Kiefer-Wolfowitz inequality, comes with an explicit finite-sample upper bound on the false-positive rate under i.i.d. assumptions. For a selected feature set of size [Formula: see text], our Dual-Parameter encoding reduces the data-qubit requirement from [Formula: see text] to [Formula: see text] at matched-feature count. This qubit reduction preserves the entangling topology but adds one additional single-qubit encoding rotation [Formula: see text] per data qubit and a Hadamard readout layer; when a SWAP-test ancilla is used, the total count becomes [Formula: see text]. We evaluate DP-QIDS on UNSW-NB15 and CIC-IDS2017 and reproduce the baseline's DDoS setting both at a richer selected feature count and under the baseline's standard 87→4 classical compression pipeline applied to both encoders, to ensure direct matched-setting comparisons at the encoder level. Ablations show that fidelity captures correlation-shifting attacks, while KL/entropy detects randomized marginals; their fusion yields consistently reliable operation. We further provide a complexity analysis, deployment architecture, and streaming variants with drift-aware recalibration. Our Dual-Parameter Quantum Intrusion Detection System (DP-QIDS) advances quantum intrusion detection from proof-of-concept toward auditable, resource-aware deployment, connecting simulator studies with practical security operations for resilient infrastructure.
Modern networks generate high-dimensional traffic that requires numerous features for effective intrusion detection and cybercrime defence, creating a critical challenge for quantum approaches, where qubit availability remains the primary bottleneck for near-term implementation. We present a quantum-enhanced framework that employs Dual-Parameter encoding, using both the polar angle θ and azimuthal phase ϕ of each qubit to encode two normalized features, combined with multi-metric anomaly scoring and calibrated false-positive control. Our detector forms a composite score [Formula: see text] that unifies quantum fidelity (global state similarity), Kullback-Leibler divergence (distributional shift), and von Neumann entropy change (uncertainty shift). The decision threshold is set by quantile calibration on benign validation, and via the Dvoretzky-Kiefer-Wolfowitz inequality, comes with an explicit finite-sample upper bound on the false-positive rate under i.i.d. assumptions. For a selected feature set of size [Formula: see text], our Dual-Parameter encoding reduces the data-qubit requirement from [Formula: see text] to [Formula: see text] at matched-feature count. This qubit reduction preserves the entangling topology but adds one additional single-qubit encoding rotation [Formula: see text] per data qubit and a Hadamard readout layer; when a SWAP-test ancilla is used, the total count becomes [Formula: see text]. We evaluate DP-QIDS on UNSW-NB15 and CIC-IDS2017 and reproduce the baseline's DDoS setting both at a richer selected feature count and under the baseline's standard 87→4 classical compression pipeline applied to both encoders, to ensure direct matched-setting comparisons at the encoder level. Ablations show that fidelity captures correlation-shifting attacks, while KL/entropy detects randomized marginals; their fusion yields consistently reliable operation. We further provide a complexity analysis, deployment architecture, and streaming variants with drift-aware recalibration. Our Dual-Parameter Quantum Intrusion Detection System (DP-QIDS) advances quantum intrusion detection from proof-of-concept toward auditable, resource-aware deployment, connecting simulator studies with practical security operations for resilient infrastructure.
Network intrusion detection systems (NIDS) must classify high-dimensional, heavily imbalanced traffic flows under tight operational constraints, and the flow features produced by modern capture tools routinely exceed the qubit budgets available on today’s noisy intermediate-scale quantum (NISQ) hardware. Existing quantum machine-learning (QML) detectors typically either assume that every extracted feature can be encoded on a dedicated qubit or apply generic dimensionality reduction that is blind to the downstream quantum encoder; in both cases the qubit budget — the binding constraint on real devices — never drives which features are encoded, and evaluation is frequently confined to ideal statevector simulation that omits shot noise, depolarizing error, and readout confusion. This paper presents ANHQ-IDS, an adaptive, noise aware hybrid quantum intrusion-detection framework that makes the qubit budget a first-class design constraint. A resource-constrained feature-selection stage scores candidate features through a composite objective jointly balancing mutual-information relevance, inter-feature redundancy, cross-split stability, and an explicit quantum-encoding cost, and greedily selects a subset sized to a target qubit budget rather than fixed a priori. The retained features are embedded through parameterized angle and second-order (ZZ) feature maps and classified by a hardware-efficient variational quantum classifier (VQC) trained with gradient-free optimizers (COBYLA and SPSA) under finite-shot sampling. To characterize behaviour under realistic hardware conditions, the classifier is evaluated on a statevector reference and under synthetic depolarizing and readout-error models, and benchmarked on CIC-IDS2017 against classical baselines (logistic regression, random forest, support vector machine) using a leakage-resistant train/validation/test protocol. On a class-balanced CIC-IDS2017 benchmark, the ZZ-encoded VQC attains macro-F1 0.766 and ROC-AUC 0.853 under exact simulation — exceeding logistic regression (0.502) and approaching a support-vector baseline, while a random forest remains strongest (0.964); performance degrades gracefully under depolarizing and readout noise, consistent with the predicted (1−p) contraction. All preprocessing, feature-selection, and quantum-training components are released as a reproducible Qiskit package with fixed seeds and recorded circuit-resource metadata (qubits, depth, gate and parameter counts).
Quantum machine learning (QML) is increasingly investigated for network intrusion detection, but the practical value of current quantum models remains uncertain because many studies rely on small simulated data sets, idealized execution, weak classical baselines, or isolated accuracy comparisons. This study develops and evaluates a resource-aware hybrid quantum-classical intrusion detection framework that combines fixed fidelity quantum kernels, repaired Quantum Kernel Alignment (QKA), a Variational Quantum Classifier (VQC), LightGBM, prototype-based kernel reduction, and probabilistic stacking. Experiments use the UNSW-NB15 benchmark under a leakage-aware preprocessing protocol and repeated evaluation across five random seeds. The experimental program covers 4- and 6-qubit representations, multiple training sizes, prototype budgets, and finite-shot configurations, yielding 260 experimental configurations/runs. The strongest quantum-assisted model, a 6-qubit QKA-VQC-LightGBM stack at 100 samples per class, obtains mean F1=0.8480, MCC=0.7092, ROC-AUC=0.9398, and PR-AUC=0.9302. Repaired QKA improves F1 from 0.8043 for the corresponding fixed kernel to 0.8089, while 50-prototype QKA attains F1=0.8257 with a more favorable kernel-workload trade-off than larger prototype budgets. Finite-shot experiments between 1,024 and 4,096 shots remain stable in simulation. However, full-data LightGBM remains stronger overall (F1=0.8957, MCC=0.8068, ROC-AUC=0.9755, PR-AUC=0.9704), and corrected statistical tests do not establish general quantum superiority. These findings motivate a Selective Quantum Intrusion Detection System (S-QIDS), in which classical inference handles high-confidence traffic and quantum processing is reserved for uncertain, novel, or high-risk observations. The study therefore reframes near-term quantum intrusion detection from unconditional quantum advantage toward measurable quantum utility, quantum-classical complementarity, and resource-aware quantum intervention.
Purpose This study aims to develop and validate a quantum-enhanced behavioral security framework that integrates a lightweight quantum obfuscation layer into classical intrusion detection systems (IDSs). The primary objective is to harden these models against post-quantum threats, specifically model extraction and feature inversion attacks, while maintaining high detection accuracy across both traditional machine learning and deep learning architectures. Design/methodology/approach A quantum feature obfuscation layer was designed using 6-qubit parameterized circuits with angle encoding and variational ansatz to nonlinearly transform behavioral features. This layer was integrated with classical classifiers (random forest, support vector machine, logistic regression) and a deep learning model multi-layer perceptron (MLP). The framework was evaluated on UNSW-NB15 and NSL-KDD datasets using Qiskit Aer simulators in Google Colab, measuring accuracy, precision, recall, F1-score, model extraction error (MEE) and feature inversion error (FIE). Findings Quantum-assisted models maintained detection performance comparable to classical baselines, with accuracy degradation of 0.7% across all architectures. Security resilience significantly improved, with a 3–4× increase in both MEE and FIE, indicating substantially enhanced resistance to model theft and feature reconstruction. The framework demonstrated improved noise tolerance under Gaussian perturbations. The MLP achieved 92.5% accuracy (classical) versus 91.8% (quantum-assisted), with 3.3× and 3.5× improvements in MEE and FIE, respectively. Research limitations/implications The evaluation was conducted entirely on quantum simulators, not capturing real hardware noise, decoherence and fidelity limitations. The threat model assumes secrecy of quantum circuit parameters, representing a form of model-level security through obscurity. Scalability is constrained by exponential simulation costs, limiting current experiments to 6 qubits. Only feedforward neural networks (MLP) were tested; advanced architectures like CNNs, LSTMs and transformers require future validation. The framework’s resilience against adversaries with partial knowledge of the ansatz structure remains unexplored. Practical implications The framework provides a pragmatic, classifier-agnostic defense layer deployable on freely accessible cloud platforms (Google Colab) without specialized quantum hardware. With only 15–25 ms inference overhead and 40–60% training overhead, it offers viable post-quantum hardening for security-critical applications. Resource-constrained environments such as edge computing nodes and IoT deployments can benefit from this approach. The demonstration that meaningful security gains (3–4× improvement) are achievable using only 6 qubits lowers the barrier for organizations to adopt quantum-assisted security measures today. Social implications As quantum computing threatens classical cryptography, protecting behavioral analytics becomes crucial for critical infrastructure, financial systems and healthcare networks. This research contributes to building resilient cyber defense mechanisms that protect sensitive data and privacy even when encryption is compromised. By democratizing access to quantum-enhanced security through cloud-based simulation platforms, the framework helps bridge the gap between institutions with varying resources, promoting more equitable cybersecurity preparedness for the post-quantum era across both developed and developing nations. Originality/value This work shifts the focus of quantum-enhanced security from pure cryptographic replacement to model-hardening, harnessing quantum state complexity as a defensive mechanism rather than pursuing quantum advantage for classification speed. It introduces a novel quantum obfuscation layer specifically designed for IDS, validated across both traditional ML and deep learning architectures. The consistent security improvements (3–4×) across classifier types confirm the approach is classifier-agnostic. The Colab-based implementation ensures reproducibility and accessibility, providing a practical foundation for future quantum-aware cyber defense research and deployment.
This survey examines quantum-enhanced machine learning techniques for intrusion detection in Internet of Things (IoT) and fog environments, synthesizing recent work on hybrid quantum-classical models, quantum convolutional neural networks (QCNNs), quantum support vector machines (QSVMs), and quantum-assisted clustering.We review five recent primary studies that apply quantum methods to IoT security, summarize their methodological choices (encoding, circuit ansatz, classical-quantum interfaces), and evaluate reported benefits and limitations with respect to accuracy, computational cost, and deployability in resource-constrained settings.The literature indicates potential gains in feature expressivity and false-negative reduction from quantum encodings and variational circuits, but practical barriers remain: limited qubit counts, noisy hardware, encoding overhead, and scarce real-world deployment studies.We identify concrete research gaps and propose directions for lightweight encodings, noise-aware hybrid architectures, federated quantum-assisted Intrusion Detection System (IDS), and standardized benchmarks for reproducible evaluation.The survey aims to guide researchers and practitioners toward scalable, explainable, and deployable quantum-enhanced intrusion detection for IoT.
Intrusion Detection Systems (IDSs) are a cornerstone of modern cybersecurity; however, their performance is increasingly constrained by high-dimensional network traffic and the scalability limitations of classical machine learning approaches. Quantum Machine Learning (QML) has recently emerged as a promising paradigm by leveraging quantum feature spaces and hybrid quantum–classical optimization. In this work, we present a unified and reproducible benchmarking framework for QML-based intrusion detection under realistic Noisy Intermediate-Scale Quantum (NISQ) constraints. The proposed framework integrates hybrid Quantum Neural Networks (QNNs) and Quantum Support Vector Machines (QSVMs) within a consistent experimental pipeline, enabling a systematic comparison of quantum models, embedding strategies, and dimensionality reduction techniques. Experiments are conducted on the NSL-KDD benchmark dataset for both binary (normal versus attack) and multiclass intrusion detection tasks. Multiple quantum embedding strategies, including angle, amplitude, and Instantaneous Quantum Polynomial (IQP) embeddings, are evaluated in conjunction with PCA-based dimensionality reduction to analyze trade-offs between expressivity, circuit complexity, and computational cost. The proposed models are benchmarked against strong classical baselines under identical preprocessing and evaluation conditions. The results demonstrate that QNN- and QSVM-based IDS models achieve competitive and, in several scenarios, superior performance compared to classical approaches, particularly in multiclass settings characterized by nonlinear and imbalanced data distributions. In addition, we provide an in-depth analysis of scalability limitations, training complexity, and NISQ feasibility, highlighting practical considerations for real-world deployment. To ensure full reproducibility, all implementation details, datasets, and experimental configurations are publicly available at: https://github.com/raidanis/QML-IDS-NSLKDD. These findings position hybrid QML as a promising complementary paradigm for next-generation intrusion detection systems, particularly in low-dimensional and high-complexity feature spaces.
Quantum machine learning (QML) for network intrusion detection (NIDS) is routinely reported to reach near-perfect accuracy, yet the most rigorous studies find that well-tuned classical models remain competitive, and that apparent quantum gains may be artefacts of classical dimensionality reduction and implicit regularisation rather than genuine quantum effects. We ask not whether a quantum model can post a high accuracy, but how quantum the advantage really is. We present a unified, reproducible QML-IDS benchmark evaluating hybrid variational quantum circuits and quantum-kernel SVMs against five honestly-tuned classical baselines across four standard NIDS datasets (NSL-KDD, UNSW-NB15, CICIDS2017, NF-ToN-IoT-v2) under one leakage-controlled protocol, with an equal-budget feature view, imbalance- and calibration-aware metrics with significance testing, and a simulated NISQ noise sweep. We introduce a quantum-attribution audit (parameter-matched classical controls, a random-feature kernel, and a regularisation sweep) that quantifies how much of any gain is genuinely attributable to the quantum component. Tuned classical models (Random Forest, XGBoost) match or exceed the quantum models on aggregate detection on every dataset, and the audit attributes this to classical preprocessing and regularisation rather than quantum effects. Two advantages survive false-discovery-rate correction: the quantum-kernel SVM out-ranks its direct classical surrogate (a random-feature kernel) on AUPRC and ROC-AUC, and a small four-qubit hybrid out-detects the best classical baseline at the 1% false-positive operating point on the distribution-shifted NSL-KDD task (p = 0.005, BH q = 0.030). Code, seeds, and splits are released; our contribution stands whether quantum wins, ties, or loses.