AN ENSEMBLE OF UNSUPERVISED DEEP LEARNING MODELS FOR CREDIT CARD FRAUD DETECTION

Authors

  • Nurudeen M. Ibrahim Nile University of Nigeria
  • Ausbeth Chiemeka Aguguo Nile University of Nigeria

DOI:

https://doi.org/10.33003/fjs-2025-0905-3379

Keywords:

Auto encoders, Credit card fraud, Deep learning, Ensemble Learning, Recurrent Neural Networks

Abstract

As the use of credit cards for transactions increases, so do frauds too. Global networking offers criminals just as many new opportunities as it do for ordinary users. The good news is that technology for detecting and preventing credit card fraud is likewise getting better with time. Machine Learning models have been incorporated in this field to reduce the cost and time it takes in analyzing credit card transactions and detect the fraudulent ones. However, current machine learning models primarily rely on supervised learning, which requires labeled data and struggles with new fraud patterns and class imbalances. Despite this, unsupervised machine learning models tend to perform worse than the supervised learning models in detecting credit card fraud, which makes them less likely to be a go-to option in this field. This research proposes an ensemble of unsupervised deep learning models, specifically Deep Auto encoders (AEs) and Recurrent Neural Networks (RNNs), to improve the performance of unsupervised models for credit card fraud detection. This research employs a quantitative methodology, utilizing secondary data from credit card transactions. The methodology involves preprocessing the data, followed by training and evaluating the models. The individual models achieved AUC scores of 0.96 and 0.82 respectively, while the ensemble model from their combination achieved an AUC score of 0.95.

References

Al-Faiz, M., Ibrahim, A., & Hadi, S. (2019). The effect of Z-Score standardization (normalization) on binary input due to the speed of learning in back-propagation neural networks. Iraqi Journal of Information & Communications Technology, 1, 4248.

Bodepudi, H. (2021). Credit card fraud detection using unsupervised machine learning algorithms. International Journal of Computer Trends and Technology, 69(8), 13.

Boucher, . (n.d.). Outlier detection methods applied to financial fraud.

Carcillo, F., Le Borgne, Y.-A., Caelen, O., Kessaci, Y., Obl, F., & Bontempi, G. (n.d.). Combining unsupervised and supervised learning in credit card fraud detection.

Confusion matrix: How to use it & interpret results [Examples]. (n.d.). Retrieved January 21, 2024, from https://www.v7labs.com/blog/confusion-matrix-guide

Credit card fraud detection | Kaggle. (n.d.). Retrieved April 19, 2023, from https://www.kaggle.com/datasets/mlg-ulb/creditcardfraud
Hassan, H., Ahmad, M. A., & Mustapha, R. (2024). An enhanced feature engineering technique for credit card fraud detection. FUDMA Journal of Sciences, 8(4), 816.

Islam, M. A., Uddin, M. A., Aryal, S., & Stea, G. (2023). An ensemble learning approach for anomaly detection in credit card data with imbalanced and overlapped classes. Journal of Information Security and Applications, 78.

Maaliw, R. R., Mabunga, Z. P., & Villa, F. T. (2021). Time-series forecasting of COVID-19 cases using stacked long short-term memory networks. In 2021 International Conference on Innovation and Intelligence for Informatics, Computing, and Technologies, 3ICT 2021 (pp. 435441).

Mohammed, A., & Kora, R. (2023a). A comprehensive review on ensemble deep learning: Opportunities and challenges. Journal of King Saud University - Computer and Information Sciences, 35(2), 757774.

Mohammed, A., & Kora, R. (2023b). A comprehensive review on ensemble deep learning: Opportunities and challenges. Journal of King Saud University - Computer and Information Sciences, 35(2), 757774.

Niu, X., Wang, L., & Yang, X. (n.d.). A comparison study of credit card fraud detection: Supervised versus unsupervised. www.aaai.org

Oghenekaro, L., & Ugwu, C. (2016). A novel machine learning approach to credit card fraud detection. International Journal of Computer Applications, 140, 4550.

Pumsirirat, A., & Yan, L. (2018). Credit card fraud detection using deep learning based on auto-encoder and restricted Boltzmann machine. International Journal of Advanced Computer Science and Applications (IJACSA), 9(1). www.ijacsa.thesai.org

Renstrm, T. H. (n.d.). Fraud detection on unlabeled data with unsupervised machine learning. KTH School of Chemistry, Biotechnology and Health.

Rezapour, M. (2019). Anomaly detection using unsupervised methods: Credit card fraud case study. International Journal of Advanced Computer Science and Applications (IJACSA), 10(11). www.ijacsa.thesai.org

Saraf, S., & Phakatkar, A. (n.d.). Detection of credit card fraud using a hybrid ensemble model. International Journal of Advanced Computer Science and Applications (IJACSA), 13(9). www.ijacsa.thesai.org

Understanding AUC - ROC curve | by Sarang Narkhede | Towards Data Science. (n.d.). Retrieved January 22, 2024, from https://towardsdatascience.com/understanding-auc-roc-curve-68b2303cc9c5

West, J., Bhattacharya, M., & Islam, R. (n.d.). Intelligent financial fraud detection practices: An investigation.

Zhang, A., Lipton, Z. C., Li, M. U., & Smola, A. J. (n.d.). Dive into deep learning.

Published

2025-05-31

How to Cite

Ibrahim, N. M., & Aguguo, A. C. (2025). AN ENSEMBLE OF UNSUPERVISED DEEP LEARNING MODELS FOR CREDIT CARD FRAUD DETECTION. FUDMA JOURNAL OF SCIENCES, 9(5), 263 - 270. https://doi.org/10.33003/fjs-2025-0905-3379