Impact Factor (2025): 6.9
DOI Prefix: 10.47001/IRJIET
The rapid
proliferation of digital payment infrastructure has established credit card
transactions as the backbone of the modern global economy, concurrently
exposing financial networks to sophisticated fraudulent activities. The
automated detection of such anomalies presents a significant algorithmic
challenge due to extreme class imbalance, as fraudulent instances typically
represent less than 0.5% of the overall transaction volume. This research
proposes a robust, machine learning-based classification architecture utilizing
a highly imbalanced dataset of 284,807 transactions, where the minority fraud
class constitutes merely 0.17% of the data. To neutralize the statistical bias
introduced by this skew, rigorous data preprocessing techniques including
Z-score standardization and stratified splitting were implemented. The
Synthetic Minority Over-sampling Technique (SMOTE) was deployed strictly within
the training environment to synthetically balance the class distributions and
prevent algorithmic convergence toward majority-class predictions. A
comparative analysis was conducted evaluating a linear Logistic Regression
classifier against a non-linear Random Forest ensemble. Empirical analysis
demonstrates that while the linear model achieved high theoretical class
separation, the Random Forest ensemble delivered superior operational
performance. By optimizing the precision-recall trade-off, achieving a
precision of 0.84 and a recall of 0.83, the ensemble model successfully
minimized false negative rates without inflating false positive rates, proving
its viability for real-world deployment in institutional financial security
systems.
Country : India
IRJIET, Volume 10, Issue 4, April 2026 pp. 61-65