Blockchain-based identity authentication offers a decentralized, secure alternative to traditional ID systems. It enables self-sovereign identity, where users control their data, reducing reliance on centralized authorities. With cryptographic keys and distributed ledgers, blockchain ensures tamper-proof verification, enhancing privacy and security. Existing ID systems, often vulnerable to breaches and fraud, could be disrupted by blockchain’s transparency and immutability. However, challenges like scalability, user adoption, and regulatory compliance must be addressed. While blockchain has the potential to replace current systems, a hybrid approach integrating with existing infrastructure is more likely in the near term.