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PROJECT ID: QNT-2025 // QUANTUM COMPUTING

Quantum Banknote Authentication

Our flagship quantum computing research: a hybrid quantum-classical machine learning model running on ODRA 5 — Poland's first superconducting quantum computer at Wrocław University of Science and Technology. The system authenticates banknotes by detecting subtle forgery patterns invisible to classical algorithms.

ODRA 5 Financial Security Quantum ML
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Classification Accuracy
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F1-Score
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Dataset Samples
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Qubits
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Research Overview

The Challenge

Counterfeit detection requires identifying subtle, non-linear patterns in financial documents. Traditional machine learning struggles with the high-dimensional feature correlations present in wavelet-transformed banknote images. Our research explores whether quantum computing can provide a computational advantage for this security-critical task.

Objective Validate quantum advantage for pattern recognition on real NISQ hardware
Dataset UCI Banknote Authentication — 1,372 samples extracted via Wavelet Transform
Output Binary classification: Authentic (Class 0) vs. Counterfeit (Class 1)

Our Approach

We implemented a Variational Quantum Classifier (VQC) that maps classical features into the quantum Hilbert space, enabling the detection of correlations that classical algorithms miss. The hybrid architecture combines quantum circuit execution on ODRA 5 with classical optimization via PyTorch's Adam optimizer.

Feature Encoding 4 wavelet features → 4 qubits via Ry rotation gates (Angle Encoding)
Ansatz Parameterized circuit with ring-like CX entanglement structure
Training Hybrid backpropagation using Parameter Shift Rule over 8 epochs
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Methodology

Data Pipeline

The UCI Banknote Authentication dataset provides 4 continuous features extracted from grayscale images via Wavelet Transform: variance, skewness, kurtosis, and entropy. Each feature is normalized and mapped to a qubit rotation angle, creating a quantum state that encodes the classical data in superposition.

Variance Statistical measure of pixel intensity distribution
Skewness Asymmetry of the wavelet coefficient distribution
Kurtosis Tailedness indicating outlier presence in transform
Entropy Information content and randomness measure

Quantum Circuit

The 4-qubit Variational Ansatz consists of parameterized Ry gates for feature encoding followed by controlled rotation gates (CX) creating entanglement. Measurement in the Z-basis produces expectation values that are mapped to classification probabilities via a parity function.

Qubits 4 superconducting qubits on ODRA 5 system
Circuit Depth 2-layer variational ansatz with trainable parameters
Entanglement Ring topology using controlled-X gates
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Technical Stack

Quantum Hardware

ODRA 5 System

Poland's first superconducting quantum computer, launched at PWr in 2025. Built for research in quantum informatics, telecommunications, and cybersecurity applications.

Quantum Framework

Qiskit ML

IBM's open-source quantum computing SDK with machine learning extensions. Provides circuit construction, simulation, and hardware execution interfaces.

Optimization

Hybrid Training

PyTorch's Adam optimizer handles classical backpropagation while quantum gradients are computed via the Parameter Shift Rule on actual hardware.

Scientific Basis

Research Foundation

Based on Havlíček et al. (2019) quantum feature maps and Mitarai et al. (2018) variational classifier architecture.

Research Team

Contributors

  • Iwo Wojtakajtis
  • Iwo Smura
  • Rafał Balicki
  • Karina Leśkiewicz
  • Maria Płatek
  • Michał Szczęsny