Blockchain-Based Payment Channel Network: Challenges and Recent Advances

Blockchains, introduced in 2008, have garnered significant attention from both academia and industry. Cryptocurrencies, such as Bitcoin, which rely on blockchains, have great commercial value. However, the transaction processing speed of blockchains falls short of the traditional financial system. To address this, payment channels have emerged as a promising research direction for improving blockchain system performance by reducing transaction acknowledgment delay and enhancing transaction throughput. Payment channel networks facilitate a large number of transactions to be executed off-chain, preserving asset security, reducing costs, and promoting blockchain scalability. Among payment channel networks, Lightning Network is deployed on Bitcoin and has demonstrated efficient performance and high economic benefits in actual operations, attracting significant attention and research. This paper systematically analyzes the research outcomes of payment channel networks, focusing on the potential attacks and development direction of Lightning Network. Existing research is refined into security attacks, privacy vulnerabilities, and challenging system assumptions while exploring and comparing recent solutions in Lightning Network. Finally, this paper emphasizes the potential of payment channel networks, identifies the challenges that need to be addressed, and advances the study of blockchain payment channel networks.