Credit Card Fraud Detection based on Ensemble Machine Learning Classifiers

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.

Credit Card Fraud, a fraudulent activity committed by stealing a credit card and using the same without knowledge or permission of the Card owner. Credit Card Fraud is usually committed by a criminal to purchase goods or services utilizing another account but the same card. Machine Learning algorithms can simplify the process of detection of fraudulent transaction. We show how various algorithms can be used to determine if the transaction is legitimate or not. We have split the dataset into test and train data. SMOTE technique has been on the train data for oversampling as the dataset being used is highly imbalanced. Machine Learning Classification techniques such as Gaussian Naive Bayes, Logistic Regression and Random Forest have been compared in this research. Based on the obtained performance measures, we can conclude that all three Machine Learning Models could be used for Fraudulent Transaction Detection.

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 usage of credit cards for online purchases has increased exponentially and so has fraud. In recent years, detecting fraud in credit card transactions has become significantly more difficult. As a result, having effective and accurate methods for detecting fraud in credit card transactions is vital. Although supervised learning algorithms have been shown to be effective in detecting credit card fraud, they have not generated substantial results. Hence, a Deep Neural Network (DNN)-based technique is proposed. The sequential model is used to construct the proposed DNN. However, the parameters of the model, such as the number of nodes and the activation function in the hidden layers, can also have an impact on its output. The proposed technique was evaluated on a credit card transaction dataset that comprised fraudulent and genuine transactions. This technique obtained the accuracy, area under curve (AUC), and precision of 99.93%, 99.99%, and 99.89%, respectively. This technique was compared with various models such as Optimized LightGBM, Multilayer Perceptron (MLP), K-Nearest Neighbor (KNN) and Support Vector Machine (SVM).

The existence of fraud in credit card transactions causes many financial losses leading to customers’ loss of trust. Fraud detection methods based on machine learning techniques prevent such losses. Despite the literature on fraud detection, there is a lack of algorithms that detect fraud with acceptable performance in the credit card fraud detection field. Therefore, this study proposed a comprehensive ensemble-based method using an efficient weighted voting strategy for credit card fraud detection that can address the previous algorithms’ weaknesses. First, since the dataset is imbalanced, the proposed method balanced the dataset by stratifying it into three different proportions of normal and fraudulent transactions (1 to 1, 1 to 4 and 1 to 9 ratios). The features in each dataset are ranked by four feature-ranking methods, and the Random Forest classifier is applied to each of them for selecting the essential features. Afterward, using the seven base classifiers and the chosen features, 12 ensembles have been developed. Besides, a weighted voting strategy is proposed, and the fraudulent transactions are detected through voting based on the base classifiers’ and ensembles’ weights, which are calculated by their performance. The computational results indicated that the suggested Eclf10 is the best ensemble and its Logistic Regression classifier also has the best performance among other base classifiers. The Eclf10 leads to 99.97% accuracy, 87.78% precision, 97.70% recall, 92.21% F1-score and 95.634% F2-score, which has a superiority over the previous ensemble-based methods (e.g. majority voting ensemble, stacking classifier, Adaboost, Gradient Boosting).

Abstract: Ability of debit card companies to detect and prevent fraudulent transactions is crucial to safeguard customers from unauthorized charges. Data Science, particularly Machine Learning, plays a pivotal role in addressing this challenge. This project aims to demonstrate the application of machine learning in Credit debit Fraud Detection by modeling a dataset of past credit card transactions, distinguishing fraudulent ones from legitimate ones. The objective is to achieve a fraudulent transactions while minimizing false positives. Debit Card Fraud Detection is a classic classification issue. A research focuses on data analysis, preprocessing, and the utilization of XGBoost on Credit Card Transaction data. To prevent overfitting, grid search is employed to fine-tune the models' hyperparameters. The performed of XGBoost and P-XGBoost is compared with further usual machine learning techniques. Surprisingly, P-XGBoost best XGBoost in fraud detection, presenting a viewpoint for effectively identifying fraudulent behavior while ensuring the privacy of clients.

One of the most serious diseases affecting people is heart disease, which also contributes significantly to the increasing death rate. Recently, Machine Learning (ML) methods have been utilized to detect and identify several types of heart disease, these methods can assist in enhancing the accuracy of heart disease classification. In this research, total ten machine learning (ML) models that’s are used, the first ML technique is Random Forest (rf) second ML technique is Decision Tree (dt), third is Support Vector Machine (svm) fourth ML techniques is K-Nearest Neighbors (knn), fifth ML technique is Logistics Regression (lr) and respectively Extra Trees Classifier (et), Gradient Boosting Classifier (gbc), Naive Bayes (nb), Ridge Classifier (ridge) and tenth ML technique is Linear Discriminant Analysis (ldr) are implemented. In addition, Recursive Feature Elimination (RFE) feature assortment method is used to find the significant features and enhance the efficiency of detecting heart disease using two text-based datasets. Finally, a detailed comparison will be implemented to presented that after smearing the feature selection method to recognize the most efficient model for detecting heart disease and then specify its severity. Some parameters, including accurateness, exactness, recollection, and F1-score, are offered to comparation the efficiency of each classifier. The actual outcomes of this research that improved the classification accurateness.

Financial transactions using credit card are being observed to be commonly accepted by the users as well as by the financial institutions. At the same time, a good number of fraudsters adopt various techniques to create inconvenience to the users and in the process the financial institutions lose goodwill or trustworthiness. However, a number of methodologies have been proposed by various researchers to counter and revoke the fraudulent activities in credit card transactions. The crux of the problem is that the fraudulent activities need to be curbed instantly if at all can be identified, when the fraudsters initiate them. In this study, a real time fraud detection system based on service oriented architecture (SOA) has been proposed to analyze the fraudulent activities in credit card transactions. The architecture is designed on the basis of Apache Kafka tool, which is used for real time streaming of transactional data to detect the fraudulent transactions. This process considers different services which form the backbone of SOA. Further, five different machine learning classifiers namely support vector machine (SVM), multilayer perceptron (MLP), random forest regressor, autoencoder and isolation forest have been considered to identify the fraudulent activities instantly with the help of SOA based real time architecture.

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.

Use of credit card is very common these days. And the number of frauds related to credit cards are also increasing. With the increase in the usage of internet, many organizations have shifted their work from offline to online. Same is the case with financial department. On one side, this thing has increased the ease of people but on the other hand, number of frauds have been tremendously increased. On one side, people are doing shopping without cash, paying bills without standing in long queues, doing booking online and on the other side fake accounts, scamming, credit card frauds have been increased resulting in huge amount of loss to financial system every year. Fraud is a criminal activity done by un authorized person. Credit card frauds are very common these days. There are many types of credit card frauds. Sometime they do fake calls or messages and sometimes they steal customer’s online information. Many techniques using machine learning models have been implemented in order to stop these types of frauds. But fraudsters are sometimes by pass theses traditional protective systems and make successful transaction. Traditional machine learning models are not capable enough to detect frauds using sequence of data. For this purpose, neural networks are recently used. In this paper, six machine learning algorithms are applied. Among them Random Forest and Extra trees classifier are best. And in case of neural networks, long short-term memory LSTM is best. Obtained results outperform the existed work that have been previously done in this field.

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.

This paper explores how to use statistical models and supervised machine learning (ML) techniques to detect and prevent fraud in credit card transactions. Using real bank data, this study applies descriptive and predictive analytics to identify patterns in fraudulent transactions and build a classifier model that can distinguish between legitimate and fraudulent behavior. In addition, this study explores two main hypotheses: the economic value of false positives compared to undetected fraud, and combining different ML techniques to enhance the effectiveness of fraud detection. The ultimate goal is to create a robust, flexible, and scalable framework that helps financial institutions and merchants reduce fraud-related losses, increase customer confidence, and optimize operational costs.

Online sales and purchases are increasing daily, and they generally involve credit card transactions. This not only provides convenience to the end-user but also increases the frequency of online credit card fraud. In the recent years, in some countries, this fraud increase has led to an exponential increase in credit card fraud detection, which has become increasingly important to address this security issue. Recent studies have proposed machine learning (ML)-based solutions for detecting fraudulent credit card transactions, but their detection scores still need improvement due to the imbalance of classes in any given dataset. Few approaches have achieved exceptional results on different datasets. In this study, the Kaggle dataset was used to develop a deep learning (DL)-based approach to solve the text data problem. A novel text2IMG conversion technique is proposed that generates small images. The images are fed into a CNN architecture with class weights using the inverse frequency method to resolve the class imbalance issue. DL and ML approaches were applied to verify the robustness and validity of the proposed system. An accuracy of 99.87% was achieved by Coarse-KNN using deep features of the proposed CNN.

As customers tendencies learn rapidly about online transactions due to the outbreak of the Covid-19 pandemic, fraudulent transactions that mimic legitimate transactions will continue to increase unabated. Over the years, fraudulent transactions have been committed but the supervised and unsupervised machine learning classifiers and fraud detection techniques could not stop the fraud from occurring at the onset. However, fraudulent cases are detected after post-occurrence thereby recognizing these techniques as non-smart detection models because fraud could only be detected using past data sets. Various fraud detection or classifier techniques using machine learning techniques such as decision trees, random forests, k-means, and neural networks have been studied. Also, the possibility of overfitting due to the branch growth associated with the decision trees is a classifier performance problem. The application of the probability axiomatic metric (PAM) to determine the accuracy of the models is a classification evaluation problem because of the relatively moderate error rate. To overcome the above shortfalls, we proposed a threshold Mahalanobis distance (TMD) classifier and adopted BETH as a performance evaluation metric. The result revealed that TMD is comparable to neural network (NN), k-means, isolation forest, XGBoost, and random forest based on the credit card data set. The analysis showed that TMD and NN have higher efficiency compared to other classifiers. This study demonstrated that the TMD classifier is unique and could be applied to extract legitimate and illegitimate transactions from customer transaction data sets. The study concludes that TMD is robust and comparable to NN and the classification errors associated with BETH are minimal compared to PAM for both TMD and NN.

With the continuous expansion of the banks' credit card businesses, credit card fraud has become a serious threat to banking financial institutions. So, the automatic and real-time credit card fraud detection is the meaningful research work. Because machine learning has the characteristics of non-linearity, automation, and intelligence, so that credit card fraud detection can improve the detection efficiency and accuracy. In view of this, this paper proposes a credit card fraud detection model based on heterogeneous ensemble, namely CUS-RF (cluster-based under-sampling boosting and random forest), based on clustering under-sampling and random forest algorithm. CUS-RF-based credit card fraud detection model has the following advantages. Firstly, the CUS-RF model can better overcome the issue of data imbalance. Secondly, based on the idea of heterogeneous ensemble learning, the clustering under-sampling method and random forest model are fused to achieve a better performance for credit card fraud detection. Finally, through the verification of real credit card fraud dataset, the CUS-RF model proposed in this paper has achieved better performance in credit card fraud detection compared with the benchmark model.