Explainable Credit Card Fraud Detection with Image Conversion

Credit card fraud resulted in the loss of $3 billion to North American financial institutions in 2017. The rise of digital payments systems such as Apple Pay, Android Pay, and Venmo has meant that loss due to fraudulent activity is expected to increase. Deep Learning presents a promising solution to the problem of credit card fraud detection by enabling institutions to make optimal use of their historic customer data as well as real-time transaction details that are recorded at the time of the transaction. In 2017, a study found that a Deep Learning approach provided comparable results to prevailing fraud detection methods such as Gradient Boosted Trees and Logistic Regression. However, Deep Learning encompasses a number of topologies. Additionally, the various parameters used to construct the model (e.g. the number of neurons in the hidden layer of a neural network) also influence its results. In this paper, we evaluate a subsection of Deep Learning topologies — from the general artificial neural network to topologies with built-in time and memory components such as Long Short-term memory — and different parameters with regard to their efficacy in fraud detection on a dataset of nearly 80 million credit card transactions that have been pre-labeled as fraudulent and legitimate. We utilize a high performance, distributed cloud computing environment to navigate past common fraud detection problems such as class imbalance and scalability. Our analysis provides a comprehensive guide to sensitivity analysis of model parameters with regard to performance in fraud detection. We also present a framework for parameter tuning of Deep Learning topologies for credit card fraud detection to enable financial institutions to reduce losses by preventing fraudulent activity.

Financial fraud is a serious threat that is expanding effects on the financial sector. The use of credit cards is growing as digitization and internet transactions advance daily. The most common issues in today's culture are credit card scams. This kind of fraud typically happens when someone uses someone else's credit card details. Credit card fraud detection uses transaction data attributes to identify credit card fraud, which can save significant financial losses and affluence the burden on the police. The detection of credit card fraud has three difficulties: uneven data, an abundance of unseen variables, and the selection of an appropriate threshold to improve the models' reliability. This study employs a modified Logistic Regression (LR) model to detect credit card fraud in order to get over the preceding difficulties. The dataset sampling strategy, variable choice, and detection methods employed all have a significant impact on the effectiveness of fraud detection in credit card transactions. The effectiveness of naive bayes, k-nearest neighbour, and logistic regression on highly skewed credit card fraud data is examined in this research. The accuracy of the logistic regression technique will be closer to 0.98%; with this accuracy, frauds may be easily detected. The fact that LR receives the highest classifier score illustrates how well LR predicts credit card theft.

Online credit card transactions have witnessed a steady year-to-year growth, making fraud detection an increasingly critical challenge. Credit card fraud detection is particularly difficult due to the extreme class imbalance between fraudulent and non-fraudulent transactions. Imbalanced data, where one class heavily dominates the other, must be addressed before effective fraud detection can be achieved. Traditional oversampling techniques such as the Synthetic Minority Over-sampling Technique (SMOTE) and its variants often generate synthetic samples without considering the importance of ranking performance in the minority class distribution, leading to suboptimal classification performance. To address this, an adaptive Weight and rank-based Minority (WRM-SMOTE) oversampling method is proposed that prioritizes the performance and its relative ranking. To the best of our knowledge, WRM-SMOTE is among the first method to combine performance-based weighting and ranking across multiple SMOTE variants for adaptive oversampling. This method transforms imbalanced datasets into balanced ones through adaptive synthetic sample generation. The process begins by computing a weight based on two componentsabsolute performance and relative ranking. This is done to provide a distinction between two variants with extremely similar performance when one outperforms the other. Our experimental results on real-world credit card fraud datasets and eleven other benchmark datasets demonstrate that WRM-SMOTE significantly improves fraud detection performance, achieving higher precision and recall while maintaining a balanced false-positive rate compared to traditional oversampling methods. The proposed method effectively enhances classification accuracy by generating synthetic samples in high-impact regions thereby improving the robustness of fraud detection models.

The increase of Credit Card (CC) fraud in recent years requires the development of fraud detection systems that are both efficient and robust. This paper explored the utilization of machine learning models, with a particular emphasis on ensemble methods, to advance the detection of CC fraud. We present an ensemble model that incorporates different classifiers to address the dataset imbalance issue that is present in most CC datasets. We employed synthetic over-sampling and under-sampling techniques in certain machine learning algorithms to tackle the same issue. To address the issue of under sampling, we implemented ensemble random sampling, which was subsequently followed by Two-Stage Thresholding (TST) to eliminate outliers. The well-known Synthetic Minority Over-sampling Technique (SMOTE) was used for over-sampling. Data was utilized to train the model and subsequently generate predictions by utilizing testing data following the pre-processing of the dataset. The proposed ensemble model outperformed conventional methods in addressing the challenges associated with CC fraud detection, as demonstrated by a comparative analysis. Our findings suggest that ensemble approaches are effective at fighting fraud, paving the way for more adaptive and resilient fraud detection systems.

Credit card fraud has caused a huge loss to both banks and consumers in recent years. Thus, an effective Fraud Detection System (FDS) is important to minimize the loss for banks and cardholders. Based on our analysis, the credit card transaction dataset is very skewed, there are much fewer samples of frauds than legitimate transactions. Furthermore, due to the data security and privacy, different banks are usually not allowed to share their transaction datasets. These problems make FDS difficult to learn the patterns of frauds and also difficult to detect them. In this paper, we propose a framework to train a fraud detection model using behavior features with federated learning, we term this detection framework FFD (Federated learning for Fraud Detection). Different from the traditional FDS trained with data centralized in the cloud, FFD enables banks to learn fraud detection model with the training data distributed on their own local database. Then, a shared FDS is constructed by aggregating locally-computed updates of fraud detection model. Banks can collectively reap the benefits of shared model without sharing the dataset and protect the sensitive information of cardholders. Furthermore, an oversampling approach is combined to balance the skewed dataset. We evaluate the performance of our credit card FDS with FFD framework on a large scale dataset of real-world credit card transactions. Experimental results show that the federated learning based FDS achieves an average of test AUC to 95.5%, which is about 10% higher than traditional FDS.

In today's socio-economic scenario, people rely heavily on credit cards.Moreover, credit cards are a requisite financial tool that enables its holders to make assets.It is true that credit cards, as a new method of payment, have become socially amenable to the masses.But nowadays, improvements in technology lead to growth in illegal activities.During credit card transactions many fraudsters can breach security and make fraudulent transactions to withdraw or transfer funds from one's account or e-wallets.The relevant literature presents many machine learning-based approaches for credit card detection, such as Logistic Regression, Decision Tree, CatBoost, Random Forest, Support Vector Machine, KNN, RNN, and CNN.The main focus has been to apply the recent development of deep learning algorithms for this purpose.Comparative analysis of both machine learning and deep learning algorithms was performed to find efficient outcomes.A machine learning algorithm was first applied to the dataset, which improved the accuracy of detection of the fraud to some extent.The proposed approaches can be implemented effectively for the real-world detection of credit card fraud.

<title>Abstract</title> Credit card fraud detection remains a critical yet challenging task due to the extreme class imbalance inherent in transaction datasets, where fraudulent activities constitute only a small fraction of the total records. To address this imbalance and enhance the detection of rare fraud instances, this study proposes a novel hybrid framework that integrates density-based clustering for data augmentation with an ensemble classification strategy optimized for high recall. In the preprocessing stage, the proposed method utilizes Density-Based Spatial Clustering of Applications with Noise (DBSCAN) to identify minority-class clusters and synthetically augment the fraud class. This step aims to preserve the intrinsic structure of fraudulent patterns while increasing their representation in the training set. Subsequently, an ensemble model comprising Random Forest (RF), K-Nearest Neighbors (KNN), and Support Vector Machine (SVM) classifiers is constructed. Final predictions are generated using a Disjunctive Voting Ensemble (DVE) strategy, wherein a transaction is classified as fraudulent if any of the base classifiers predicts it as such. This permissive voting mechanism prioritizes recall, thereby minimizing the risk of undetected fraudulent transactions. Extensive experiments conducted on three publicly available credit card fraud imbalanced datasets containing transaction records from European credit cardholders in 2023, providing a realistic fraud detection scenario. Computational efficiency in both training and testing is achieved using the Anaconda Navigator (Spider-Python 3.12) environment. The comparative analysis shows that the proposed DBSCAN-augmented DVE framework delivers notable improvements over traditional ensemble approaches and single-model baselines, particularly in recall and F1-score, while preserving consistently high precision. This approach proves to be both robust and interpretable, making it highly applicable to real-world fraud detection scenarios characterized by severe class imbalance. The results are especially compelling, achieving recall and F1-scores as high as 99.5% and 99.8% respectively, and consistently maintaining a perfect accuracy and precision of 100% across all imbalanced datasets. This study highlights the effectiveness of hybrid ensemble approaches in combating credit card fraud. The findings lay the groundwork for developing more resilient and adaptive fraud detection systems, which are crucial in countering the evolving tactics of fraudsters. The proposed model marks a significant advancement in securing financial transactions and mitigating risks in an increasingly digital economy.

This paper uses a classifier named random forest to detect credit card fraud. Credit card fraud is one of the main issues in the economic industry. To construct a credit card fraud detection system, a certain amount of samples is required. In this paper, a dataset containing 284,807 credit card transactions is used. This dataset has gone through the PCA transformation and includes 492 frauds out of 284,807 transactions. Based on the huge amount of data and imbalanced samples, this paper compresses the dataset and uses the synthetic minority over-sampling technique (SMOTE) to address the problem of imbalanced samples. Also, in this paper, we use random forest as a classification model while constructing the fraud detection system/method.

Credit card fraud is a common occurrence in today’s society because the majority of us use credit cards as a form of payment more frequently. This is the outcome of developments in technology and an increase in online transactions, which have given rise to frauds that have caused significant financial losses. In order to detect fraud in credit card transactions, efficient and effective approaches are needed. In this study, we developed a hybrid CNN‐SVM model for detecting fraud in credit card transactions. The effectiveness of our suggested hybrid CNN‐SVM model for detecting fraud in credit card transactions was tested using real‐world public credit card transaction data. The architecture of our hybrid CNN‐SVM model was developed by replacing the final output layer of the CNN model with an SVM classifier. The first classifier is a fully connected layer with softmax that is trained using an end‐to‐end approach, whereas the second classifier is a support vector machine that is piled on top by deleting the final fully connected and softmax layer. According to experimental results, our hybrid CNN‐SVM model produced classification performances with accuracy, precision, recall, F1‐score, and AUC of 91.08%, 90.50%, 90.34%, 90.41, and 91.05%, respectively.

The widespread use of credit cards has led to an increase in fraud. Credit card fraud detection involves identifying and preventing fraudulent transactions, either in real-time or post-occurrence. This paper seeks to create an advanced credit card fraud detection model via data mining. The proposed method comprises four essential steps: data acquisition, preprocessing, feature selection, and fraud detection. A recent balanced dataset is acquired, containing 28 anonymized features about the credit card transactions, along with the transaction amount and the transaction label (normal or fraud). The dataset is then explored to clean it and ensure its integrity. Feature selection is executed via the Energy Valley Optimization (EVO) metaheuristic method, employing the accuracy value of the Light Gradient Boosting Machine (LGBM) as the fitness function. This results in a 30% reduction in features. The reduced dataset is then input into the classification step, where an ensemble soft voting model is applied. This model encompasses Extra Trees, eXtreme Gradient Boosting (XGBoost), and Categorical Boosting (CatBoost) classifiers. The proposed model averages the probability of the three classifiers for each label and outputs the label with the highest average probability. The proposed method is assessed using recall, precision, accuracy, and F1-score, attaining 99.89%, 99.58%, 99.74%, and 99.74%, respectively. The proposed approach is evaluated against existing machine learning classifiers and relevant studies using the same dataset, showcasing enhanced performance and confirming its efficacy in identifying credit card fraud.

Application of Credit Card Fraud Detection: Based on Bagging Ensemble Classifier

Nowadays, in the digital era, the use of credit cards is widespread. People buy and sell goods from home. E-commerce brings a boom to the lifestyle of the people, for the working family, it is a preferable tool to purchase and pay through online mode in order to save the time and visiting hours. However, with the increasing use of credit cards, there have also been a lot of cases of credit card frauds that augmented much in the corona period. Fake credit card transactions significantly affect financial institutions, banks, and clients, whereas fraudsters try to develop new ways of committing fraud daily. To avoid credit card fraud and maintain the credibility of our clients, we need to build a model for credit card detection. There are the various machine learning tools that can be applied in detection of such frauds, these tools can be used to design an enhanced model to detect credit card frauds efficiently. In this view, the study presents a feature selection technique approach of machine learning with different classifiers. The study proposed an optimization algorithm using ‘Firefly’ for feature selection with four different classifiers: neural network, k-nearest neighbors, Support Vector Machine, and decision tree. The performance of all these four classifiers is compared on the basis of accuracy parameter.

Abstract: With the increasing reliance on online transactions across sectors such as banking, telecommunications, insurance, and e-commerce, credit card fraud has emerged as a critical concern. The widespread use of electronic payment systems, particularly credit and debit cards, has made fraudulent activities more prevalent and sophisticated. Credit card fraud detection presents a complex classification problem that can be effectively addressed using machine learning (ML) techniques. This study explores the capabilities of ML algorithms in detecting fraudulent credit card transactions by examining both the challenges and opportunities in this domain. Adopting a mixed-method approach that combines a comprehensive literature review with experimental evaluation, the study investigates how past transaction data distinguishing between legitimate and fraudulent activities can be modeled to classify new transactions accurately. The research advocates for a progressive transition towards hybrid models that integrate machine learning with deep learning techniques to enhance the robustness and adaptability of fraud detection systems.

The explosive expansion of E-Commerce has led to a corresponding surge in credit card fraud as more people use their cards to make transactions online. Credit card fraud is on the rise as credit cards become the preferred method of payment for both online and in-store purchases. In practice, fraudulent and legitimate transactions coexist, and basic pattern-matching approaches are typically insufficient to identify fraud effectively. While Artificial Neural Networks (ANNs) offer several advantages, it's important to note that they require careful tuning, validation, and ongoing monitoring to ensure optimal performance. Additionally, the interpretability of ANNs can be a challenge, and efforts are being made to enhance model interpretability in the context of fraud detection. Identifying fraudulent transactions while avoiding false positives is the main objective of a credit card fraud detection system that uses ANNs effectively and correctly. Therefore, for credit card issues to reduce their loss, it is crucial that they implement reliable fraud detection systems. Various forms of credit card fraud may now be detected using cutting-edge methods based on Artificial Intelligence (AI), Data mining, Fuzzy logic, Machine learning (ML), sequence alignments, Genetics Programming, etc. An effective system for detecting credit card fraud requires a thorough grasp of all these methods. Using a set of predetermined criteria, this study examines the various neural network techniques currently in use for credit card fraud detection and provides an overall rating for each. The result shows 98% accuracy and 96% recall for the credit card fraud detection system.

Unbalanced Credit Card Fraud Detection Data: A Machine Learning-Oriented Comparative Study of Balancing Techniques