HCVC: A High-Capacity Off-Chain Virtual Channel Scheme Based on Bidirectional Locking Mechanism
Songyou Xie, Lijun Xiao, Dezhi Han, Kun Xie, Xiong Li, Wei Liang
Abstract
As one of the key components of Web 3.0, the security of cryptocurrency is essential to its development and application. A Payment Channel Network (PCN) enhances transaction confirmation speed and throughput by executing blockchain transactions off-chain. However, existing PCN protocols have problems like privacy leaks and offline and challenges in meeting privacy and security demands. Due to such problems, we propose in this work High-Capacity Virtual Channel (HCVC) scheme to achieve payment across PCNs. As a lightweight virtual channel protocol based on the unspent transaction output model, HCVC uses a bidirectional locking mechanism to lock the collateral on payment channels to increase the capacity of the virtual channel. Additionally, a bidirectional punishment mechanism is introduced to deter malicious nodes, maintain balance security, and enable secure peer-to-peer transactions across PCNs, as all phases of HCVC can be performed off-chain without confirming transactions on-chain. Experimental analysis shows that the HCVC performs better in n-path PCNs. Compared to Donner, the communication overhead of HCVC in the open and resolve(undesirable) phases can be reduced by 39% and 37%, respectively, effectively reducing the overhead of transactions and enhancing the transaction throughput of the blockchain.