Security Challenges and Defense Strategies in Blockchain Systems

In the general use of blockchain technology, its decentralization, transparency, and immutability have demonstrated significant value in fields such as finance, logistics, healthcare, and public administration. However, this technology also faces a series of security and performance challenges. Especially in aspects of resisting malicious attacks, there is yet room for refinement. The integrated application of blockchain technology has gradually become an important driving force for new technological innovation and industrial transformation. Various industries have increased investment, research and development, and application landing of blockchain related technologies. The integration of blockchain technology with the real economy is accelerating. While blockchain technology and applications are rapidly developing, many industries are still in the exploration stage of blockchain applications. In the process of exploring the implementation of blockchain applications, obstacles to security risks have gradually emerged. Although blockchain provides reliable security guarantees at the underlying technology, attackers can still find security issues in the blockchain system and carry out attacks. The losses caused by network attacks are increasing year by year. This paper recalls the development and core principles of blockchain technology while focusing on major attack methods and summarizes the existing defense strategies against these threats.