Most self-service payment terminals require network connectivity for processing electronic payments. The necessity to maintain network connectivity increases costs, introduces cybersecurity risks, and significantly limits the number of places where the terminals can be installed. Leading payment service providers have proposed offline payment solutions that rely on algorithmically generated payment tokens. Existing payment token solutions, however, require complex mechanisms for authentication, transaction management, and most importantly, security risk management. In this paper, we present VolgaPay, a blockchain-based system that allows merchants to deploy secure offline payment terminal infrastructure that does not require collection and storage of any sensitive data. We design a novel payment protocol which mitigates security threats for all the participants of VolgaPay, such that the maximum loss from gaining full access to any component by an adversary incurs only a limited scope of harm. We achieve significant enhancements in security, operation efficiency, and cost reduction via a combination of polynomial multi-hash chain micropayment channels and blockchain grafting for off-chain channel state transition. We implement the VolgaPay payment system, and with thorough evaluation and security analysis, we demonstrate that VolgaPay is capable of delivering a fast, secure, and cost-efficient solution for offline payment terminals.

中文翻译：

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离线支付终端的全系统安全性

大多数自助支付终端需要网络连接来处理电子支付。保持网络连接的必要性增加了成本，引入了网络安全风险，并显着限制了可以安装终端的地点数量。领先的支付服务提供商提出了依赖于算法生成的支付令牌的离线支付解决方案。然而，现有的支付令牌解决方案需要复杂的身份验证机制、交易管理机制，最重要的是安全风险管理机制。在本文中，我们介绍了 VolgaPay，这是一个基于区块链的系统，允许商家部署安全的离线支付终端基础设施，不需要收集和存储任何敏感数据。我们设计了一种新颖的支付协议，可以减轻对 VolgaPay 的所有参与者的安全威胁，这样对手获得对任何组件的完全访问权所造成的最大损失只会造成有限范围的伤害。我们通过多项式多哈希链小额支付通道和用于链下通道状态转换的区块链嫁接相结合，在安全性、运营效率和成本降低方面实现了显着增强。我们实施了 VolgaPay 支付系统，通过全面的评估和安全分析，我们证明了 VolgaPay 能够为线下支付终端提供快速、安全和具有成本效益的解决方案。我们通过多项式多哈希链小额支付通道和用于链下通道状态转换的区块链嫁接相结合，在安全性、运营效率和成本降低方面实现了显着增强。我们实施了 VolgaPay 支付系统，通过全面的评估和安全分析，我们证明了 VolgaPay 能够为线下支付终端提供快速、安全和具有成本效益的解决方案。我们通过多项式多哈希链小额支付通道和用于链下通道状态转换的区块链嫁接相结合，在安全性、运营效率和成本降低方面实现了显着增强。我们实施了 VolgaPay 支付系统，通过全面的评估和安全分析，我们证明了 VolgaPay 能够为线下支付终端提供快速、安全和具有成本效益的解决方案。