Purpose - This systematic review explores the intricacies of privacy and safety in Decentralized Finance (DeFi) and blockchain systems. We focus on major privacy attacks and vulnerabilities and at the same time, we examine how security functions get distributed, highlight the gaps where users end up exposed, and look closely at the latest research on DeFi security.
Design/methodology/approach - A systematic literature review was conducted, analyzing peer-reviewed articles.
Findings - This review reveals a persistent gap between academic research priorities and real-world risk in DeFi security. Smart contract reentrancy is the most studied attack, yet the attacks causing the greatest financial damage to remain underrepresented in the literature. Privacy and security emerge as deeply interconnected, a compromise in user privacy significantly increases exposure to financial exploitation.
Research limitations/implications - Only peer-reviewed literature published in Scopus from 2017 to 2026 is included in this review, resulting in relevant studies from other sources likely being excluded. Different attacks, such as flash loan exploits and cross-chain bridge attacks, are not yet well reported in the academic literature. Future research will need to address these gaps and to develop frameworks that consider privacy and security together instead separately.
Originality/value - Prior research has typically analyzed security and privacy in blockchain environments as being two separate disciplines. This literature review provides an integrated perspective on the connection between privacy threats and security risks, at the levels of the network, the protocol, and the user. As a result, we aim to deliver a more comprehensive account of the many types of risk that are inherent to decentralized systems.
Keywords - Blockchain Cross Chain Attacks, Blockchain Deanonymization, Blockchain Private Key Theft, Decentralized Finance Attacks, Decentralized Finance Flash Loan Attacks
Paper type - Literature review

JEL Classification: G20, G23, O33