A SURVEY ON BLOCKCHAIN-DRIVEN FEDERATED LEARNING AND EXPLAINABLE AI FRAMEWORKS FOR SECURE FRAUD DETECTION IN DEFI

Abstract

The rapid evolution of Decentralized Finance (DeFi) has introduced unprecedented financial innovations alongside complex fraud vectors that challenge conventional security mechanisms.Traditional fraud detection systems rely heavily on centralized data aggregation and opaque machine learning models, which are fundamentally incompatible with the decentralized and trust-minimized architecture of blockchain ecosystems.Emerging paradigms such as Federated Learning (FL) and Explainable Artificial Intelligence (XAI) have been independently proposed to address privacy and transparency concerns in financial systems.However, despite significant progress in each domain, the literature reveals methodological fragmentation and architectural disconnection among blockchain-based fraud detection, privacy-preserving learning, and explainability mechanisms.This study critically reviews existing research on traditional finance fraud detection, blockchain analytics, federated learning security, XAI applications, and blockchain-FL integration frameworks.Through comparative and analytical synthesis, it identifies critical research gaps, including the absence of unified decentralized fraud architectures, insufficient explainability in on-chain systems, and limited governance models for federated financial intelligence.This study establishes a theoretical and technological foundation for an integrated blockchain-driven FL-XAI framework tailored for DeFi fraud detection.