Published Paper Details:

Blockchain technology has revolutionized digital security by enabling decentralized, tamper-resistant, and transparent data management. However, with its increasing adoption, blockchain faces a growing number of security threats, including smart contract vulnerabilities, 51% attacks, Sybil attacks, cross-chain interoperability risks, and the potential impact of quantum computing. Ensuring robust security in blockchain systems is crucial for applications such as things like decentralized finance (DeFi), tracking goods in the supply chain, and verifying digital identities.This survey provides a systematic review of blockchain security threats and mitigation strategies. We categorize vulnerabilities based on blockchain layers-- network, consensus, and application--and analyze emerging defense mechanisms. Advanced solutions such as artificial intelligence (AI)-driven anomaly detection, automated smart contract verification, Zero-Knowledge Proofs (ZKPs) for privacy preservation, and quantum-resistant cryptographic techniques are explored. Additionally, we discuss blockchain forensic artificial intelligence (AI)-driven anomaly detection, automated smart contract verification, Zero-Knowledge Proofs (ZKPs) for privacy preservation, and quantum- resistant cryptographic techniques. Additionally, blockchain forensic techniques are being developed to detect fraudulent activities and illicit transactions. This survey provides a comprehensive review of block-chain security threats and mitigation strategies. We categorize vulnerabilities based on blockchain layers--network, consensus, and application-- and analyze emerging defense mechanisms. By consolidating recent advancements and identifying open research challenges, this paper aims to guide future research in developing secure and resilient blockchain architectures. II. SECURTY THREATS IN BLOCKCHAIN techniques for detecting fraud and illicit transactions.By A. Network Layer Attacks consolidating recent advancements and identifying open research challenges, this paper serves as a roadmap for future research in blockchain security. Our analysis highlights the need for adaptive, AI-enhanced security frameworks and novel cryptographic approaches to address evolving threats. This survey aims to assist researchers and industry professionals in developing secure and resilient blockchain architectures for the next decade and application layers. Additionally, we explore AI- driven security mechanisms and cryptographic advancements to enhance blockchain security.