Privacy-Preserving Credit Card Approval Using Homomorphic SVM: Toward Secure Inference in FinTech Applications
Faneela, Baraq Ghaleb, Jawad Ahmad, William J. Buchanan, Sana Ullah Jan
TL;DR
The paper tackles the challenge of performing credit-scoring classification in privacy-sensitive finance by enabling secure inference over encrypted data. It introduces PP-FinTech, a CKKS-based encrypted SVM using a hybrid Polynomial–RBF kernel and an adaptive threshold to maintain robustness under encryption noise, with an optimized SIMD-enabled inference pipeline. The approach trains the SVM in plaintext on an 80:20 split of the Credit Card Approval dataset and then encrypts the model to perform inference securely, achieving performance comparable to plaintext baselines while providing strong privacy guarantees. The results demonstrate practical latency (approximately 44.9 ms per sample) and scalable batch processing, highlighting the method's potential for secure fintech ML deployments.
Abstract
The growing use of machine learning in cloud environments raises critical concerns about data security and privacy, especially in finance. Fully Homomorphic Encryption (FHE) offers a solution by enabling computations on encrypted data, but its high computational cost limits practicality. In this paper, we propose PP-FinTech, a privacy-preserving scheme for financial applications that employs a CKKS-based encrypted soft-margin SVM, enhanced with a hybrid kernel for modeling non-linear patterns and an adaptive thresholding mechanism for robust encrypted classification. Experiments on the Credit Card Approval dataset demonstrate comparable performance to the plaintext models, highlighting PP-FinTech's ability to balance privacy, and efficiency in secure financial ML systems.
