International Journal of Scientific Research and Engineering Development

Blockchain has been tested in supply chains, healthcare, and finance and promises transparent, tamper-resistant records. However, the technology also raises new security issues: cross-chain links pose new risks, endpoints and smart contracts are regularly attacked, and industry and regional legal and regulatory requirements vary. This paper identifies lingering issues and potential solutions (post-quantum cryptography, artificial intelligence-powered evaluation, and independent identity), illustrates practical use fields (healthcare and port supply chain), and describes the core elements of security (consensus and cryptography). The key conclusion is that, while blockchain can boost trust in certain contexts, its practical security necessitates layered defenses, meticulous engineering, and regulatory alignment.