Saved in:
Bibliographic Details
Main Authors: Khan, Afsana, Thij, Marijn ten, Tang, Guangzhi, Wilbik, Anna
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.19207
Tags: Add Tag
No Tags, Be the first to tag this record!
Table of Contents:
  • Federated learning (FL) is a privacy-preserving machine learning paradigm that enables multiple parties to collaboratively train models on privately owned data without sharing raw information. While standard FL typically addresses either horizontal or vertical data partitions, many real-world scenarios exhibit a complex hybrid distribution. This paper proposes Hybrid Federated Learning (HybridFL) to address data split both horizontally across disjoint users and vertically across complementary feature sets. We evaluate HybridFL in a financial crime detection context, where a transaction party holds transaction-level attributes and multiple banks maintain private account-level features. By integrating horizontal aggregation and vertical feature fusion, the proposed architecture enables joint learning while strictly preserving data locality. Experiments on AMLSim and SWIFT datasets demonstrate that HybridFL significantly outperforms the transaction-only local model and achieves performance comparable to a centralized benchmark.