In today’s cryptocurrency, the Payment Channel Network (PCN) is noticed as one of the most gifted off-chain solutions for scalability issues. Besides this, it consumes lesser transaction fees and low transaction confirmation time. However, security and privacy issues need to be addressed appropriately to make the solution even more effective. Most of the existing HTLC (Hashed Time-Lock Contract) protocols revealed the sender’s information to the intermediate users in the payment route. In this work, we propose an effective secure and privacy-preserving Payment Channel Network protocol, named Neo Hashed Time-Lock Commitment ($n$-HTLC) protocol. ($n$-HTLC) does not require the sender to send any information to each intermediate user along the payment route, thus preserves the identity of the sender. But, ($n$-HTLC) is not compatible with Sphinx onion packet format. Therefore, a symmetric key encryption-based protocol called kTLC has been proposed. kTLC is compatible with the Sphinx onion packet format, which is used in the current Lightning network atop of the Bitcoin blockchain network. The security of both $n$-HTLC and kTLC are proved using the Universal Composability (UC) framework. It is observed that both ensure that no attacker can extract information on the payment route if at least one of the users in the path is honest. To analyze the performance of both $n$-HTLC and kTLC payment protocol, we conduct experiments using the snapshots of Ripple network¹, Lightning network², and synthetic network of Mazumdar and Ruj (2020). Our experimental results show that both $n$-HTLC and kTLC outperform state-of-the-art off-chain payment protocols in terms of computational and communication overhead.

在当今的加密货币中，支付渠道网络（PCN）被视为解决可伸缩性问题的最有天赋的链下解决方案之一。除此之外，它消耗更少的交易费用和较短的交易确认时间。但是，需要适当解决安全性和隐私问题，以使解决方案更加有效。大多数现有的HTLC（哈希时间锁定合同）协议在付款路线中向中间用户透露了发件人的信息。在这项工作中，我们提出了一种有效的安全且具有隐私保护功能的支付渠道网络协议，称为Neo Hashed Time-Lock Commitment（$ñ$- HTLC）协议。（$ñ$- HTLC）不需要发送者的任何信息沿支付途径的每个中间用户发送，从而保留了发送者的身份。但， （$ñ$- HTLC）不兼容的狮身人面像洋葱包格式。因此，提出了一种基于对称密钥加密的协议，称为kTLC。k TLC与Sphinx洋葱数据包格式兼容，该格式在比特币区块链网络顶部的当前Lightning网络中使用。两者的安全性$ñ$-HTLC和kTLC已使用通用组合（UC）框架进行了证明。可以观察到，如果路径中的至少一个用户是诚实的，两者都确保没有攻击者可以提取有关支付路径的信息。分析两者的性能$ñ$-HTLC和kTLC支付协议，我们使用Ripple网络¹，Lightning网络²以及Mazumdar和Ruj（2020）的合成网络的快照进行实验。我们的实验结果表明$ñ$就计算和通信开销而言，HTLC和kTLC优于最新的脱链支付协议。