
2 RELATED WORK
Fraud detection algorithms in credit card transac-
tions employ Machine Learning techniques to ef-
fectively identify fraudulent activities. Traditional
approaches predominantly use centralized learning
models such as Decision Trees (DT), Random Forests
(RF), Logistic Regression (LR), Support Vector Ma-
chines (SVM), Extreme Gradient Boosting (XGB),
and unsupervised methods like Generative Adversar-
ial Networks (GAN), Auto-Encoders (AE), Restricted
Boltzmann Machines (RBM), and One-Class SVM
(OCSVM) (G. Bejjanki and Narsimha, 2018), (X. Niu
and Yang, 2019). While effective, these methods
face scalability and data privacy challenges due to
their centralized nature. For example, a study us-
ing the UCI Credit Card Dataset, comprising 284,807
transactions, highlighted the imbalanced nature of the
data with only 492 fraudulent transactions, impacting
model accuracy.
Federated Learning (FL) has emerged as a promis-
ing alternative, addressing concerns over data security
and privacy inherent in centralized models (M. Fahmi
and Nagati, 2016), (K. Chen and Zhang, 2019). FL
enables collaborative model training on distributed
data sources without sharing sensitive information,
thereby enhancing privacy while improving model
performance. Recent studies, such as one involving a
federated dataset of over 1 million transactions from
multiple banks, have demonstrated FL’s effectiveness
in real-time credit card fraud detection, showing sig-
nificant improvements compared to traditional cen-
tralized models (K. Chen and Zhang, 2019).
In Deep Learning, unsupervised models like AE
and RBM have shown high accuracy rates (88% to
94%) in detecting credit card fraud when integrated
into Federated Learning frameworks (al., 2019), (Su-
varna and Kowshalya, 2020). For instance, using the
IEEE-CIS Fraud Detection dataset, with over 590,000
records, these models required careful parameter tun-
ing and computational resources but offered robust
performance in identifying complex fraud patterns.
Privacy-preserving strategies such as combining FL
with differential privacy and homomorphic encryp-
tion further bolster the security of fraud detection sys-
tems (Albertio, 2019). (al., 2020).
Hybrid techniques integrating Decision Trees,
clustering algorithms, pairwise matching, Neural Net-
works, and genetic algorithms are also being explored
to predict fraud in various transactional datasets
citeb15, (Dornadula and Geetha, 2019). For exam-
ple, a hybrid approach on the European cardholders
dataset, consisting of 284,807 records, leveraged local
and global model characteristics to optimize perfor-
mance while minimizing communication overhead.
To address class imbalance challenges in fraud
detection datasets, various methods including cost-
sensitive Deep Learning approaches and resampling
techniques like SMOTE, EUS-Bag, and PSOAANN
have been developed (Kamaruddin and Ravi, 2016).
These techniques aim to balance dataset distribu-
tions and enhance model robustness against rare fraud
cases. A study using the Kaggle Credit Card Fraud
Detection dataset, which includes 284,807 transac-
tions, found that applying SMOTE improved the de-
tection rate of fraudulent transactions significantly,
though implementation requires careful consideration
to avoid biases and maintain computational efficiency.
Recent works have further advanced fraud detec-
tion in the FL framework. Salam et al. (2023) pro-
posed a Federated Learning model for credit card
fraud detection, incorporating data balancing tech-
niques to address privacy and class imbalance. Sim-
ilarly, Li and Walsh (2024) introduced FedGAT-
DCNN, combining Graph Attention Networks and di-
lated convolutions in FL to enhance fraud detection.
Our work builds upon these studies by integrating
SMOTE directly into FL and optimizing key FL pa-
rameters, such as the fraction of participating institu-
tions (F) and the number of local epochs (E), to en-
hance model performance and scalability.
Compared to existing approaches, our work offers
several significant value additions:
• Privacy Protection Through Federated Learn-
ing. Unlike traditional approaches that require
sharing raw data, our method allows secure col-
laboration among financial institutions, address-
ing data privacy concerns.
• Enhanced Fraud Detection with SMOTE. By
using SMOTE to balance the data, our ap-
proach overcomes the challenge of class imbal-
ance, thereby improving the performance of pre-
dictive models.
• Comparative Analysis of LSTM and CNN
Models. Our study provides a detailed compara-
tive analysis of LSTM and CNN networks within
a Federated Learning framework, offering valu-
able insights into the effectiveness of these mod-
els for credit card fraud detection.
• Practical Applicability for Financial Institu-
tions. Experimental results demonstrate that the
combination of SMOTE and LSTM within the
Federated Learning system yields the best results,
highlighting the superiority of the LSTM model
in handling sequential transaction data.
In summary, the combination of centralized and
Federated Learning models, along with advanced
Enhanced Credit Card Fraud Detection Using Federated Learning, LSTM Models, and the SMOTE Technique
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