Autonomous Systems (ASes) that constitute the Border Gateway Protocol (BGP) have different interests and route policies. When actual route announcements exceed expected boundaries, route leakages can occur, leading to network security incidents caused by route redirection. In the propagation of BGP route information, ASes unconditionally trust and accept the routes declared by neighboring ASes. Additionally, each AS independently configures its own local policies and keeps this information secret, which complicates the verification of this route policy. This has been a persistent and unresolved challenge in the field of BGP security. Blockchain technology, with its inherent characteristics of decentralization, traceability, immutability, and transparency, offers a promising infrastructure for digital resource authentication and trust among ASes, potentially serving as a key technology for addressing the threat of route leakages. This study first clearly defines the relationships between neighboring ASes, as well as between the GR (Gao-Rexford) model and BGP route policies, elucidating the root causes of route leakages and the challenges in their prevention. Additionally, it reviews the research on traditional solutions to route leakages, focusing on their strengths, weaknesses, and unresolved issues. Subsequently, it proposes the advantages and technical approaches of using blockchain technology to defend against BGP route leakages and explores the principles and application characteristics of typical solutions. Finally, it discusses the existing challenges and outlines future research directions.