HCVC: A High-Capacity Off-Chain Virtual Channel Scheme Based on Bidirectional Locking Mechanism

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.