This paper examines the transformative role of blockchain technology in enhancing modern cybersecurity frameworks against increasingly sophisticated threats. The study highlights how the decentralized and cryptographic nature of blockchain mitigates systemic vulnerabilities, specifically addressing the risks associated with Single Points of Failure and DDoS attacks. Furthermore, the integration of blockchain with artificial intelligence and cloud computing is explored as a proactive strategy for real-time threat detection and autonomous response. Special emphasis is placed on securing the Internet of Things (IoT) ecosystem through decentralized identification and authentication protocols. Finally, the research addresses critical implementation challenges such as energy efficiency and regulatory frameworks, positioning blockchain as a fundamental standard for future digital integrity.