[论文解读] Incentivized Delivery Network of IoT Software Updates Based on Trustless Proof-of-Distribution

Oded Leiba, Yechiav Yitzchak+3 more|arXiv (Cornell University)|May 11, 2018

Blockchain Technology Applications and Security被引用 4

一句话总结

本文提出了一种去中心化的、基于激励的物联网软件更新分发网络，利用基于区块链的智能合约和零知识从属支付（ZKCP）技术，确保分发者获得无信任、公平的补偿。通过智能合约将供应商的承诺绑定到微支付，并使用ZKCP生成不可伪造的分发证明，该系统实现了可扩展、安全且可审计的更新分发，无需依赖中心化基础设施或信任中间方。

ABSTRACT

The prevalence of IoT devices makes them an ideal target for attackers. To reduce the risk of attacks vendors routinely deliver security updates (patches) for their devices. The delivery of security updates becomes challenging due to the issue of scalability as the number of devices may grow much quicker than vendors' distribution systems. Previous studies have suggested a permissionless and decentralized blockchain-based network in which nodes can host and deliver security updates, thus the addition of new nodes scales out the network. However, these studies do not provide an incentive for nodes to join the network, making it unlikely for nodes to freely contribute their hosting space, bandwidth, and computation resources. In this paper, we propose a novel decentralized IoT software update delivery network in which participating nodes referred to as distributors) are compensated by vendors with digital currency for delivering updates to devices. Upon the release of a new security update, a vendor will make a commitment to provide digital currency to distributors that deliver the update; the commitment will be made with the use of smart contracts, and hence will be public, binding, and irreversible. The smart contract promises compensation to any distributor that provides proof-of-distribution, which is unforgeable proof that a single update was delivered to a single device. A distributor acquires the proof-of-distribution by exchanging a security update for a device signature using the Zero-Knowledge Contingent Payment (ZKCP) trustless data exchange protocol. Eliminating the need for trust between the security update distributor and the security consumer (IoT device) by providing fair compensation, can significantly increase the number of distributors, thus facilitating rapid scale out.

研究动机与目标

• 解决在快速增长的设备生态系统中，集中式物联网软件更新分发所面临的可扩展性和可用性挑战。
• 通过引入经济激励机制，解决去中心化更新网络中的搭便车问题，激励节点贡献带宽、存储和计算资源。
• 通过使用零知识从属支付（ZKCP）的公平交换机制，消除分发者与物联网设备之间的信任需求。
• 使供应商能够监控更新分发情况，优先处理关键补丁，并通过区块链验证的证明确保软件完整性。
• 设计一个高可用、可审计且与现有区块链平台（如以太坊）兼容的系统。

提出的方法

• 系统在公共区块链上使用智能合约，将供应商对特定物联网设备的更新交付承诺绑定到微支付。
• 分发者仅在提供不可伪造的分发证明后才能获得补偿，该证明通过零知识从属支付（ZKCP）协议生成。
• ZKCP支持无信任交换：分发者发送更新，物联网设备通过签名挑战生成证明，表明已接收更新。
• 分发证明可密码学验证，并可发布到区块链以申领支付，确保公平性和不可逆性。
• 系统利用zk-SNARKs技术，确保仅正确交付能产生有效证明，伪造概率可忽略不计。
• 优化措施包括批量交易和公钥索引，以减少区块链存储和交易负载。

实验结果

研究问题

• RQ1 去中心化的物联网更新网络如何在不依赖中心化基础设施的情况下实现高可用性和可扩展性？
• RQ2 如何有效建模经济激励机制，以确保非供应商节点积极参与更新分发？
• RQ3 像ZKCP这样的无信任交换协议能否消除分发者与物联网设备之间的信任需求，同时确保公平补偿？
• RQ4 在无权限、去中心化的网络中，通过何种机制可确保软件更新的完整性和真实性？
• RQ5 系统如何实现可审计性和可扩展性，以支持供应商特定的优先级，如关键补丁或客户特定的分发？

主要发现

• 通过在激励节点间去中心化分发，该系统实现了可扩展、容错且高可用的物联网更新分发网络。
• 分发证明在密码学上不可伪造，概率可忽略不计，确保仅有效交付可获得支付。
• 区块链上的智能合约不可逆地强制执行供应商承诺，保证分发者仅在成功交付后获得支付。
• 使用ZKCP确保公平交换：分发者仅在交付更新后获得支付，设备仅在实际接收更新后才签名。
• 系统支持可编程激励，允许供应商通过智能合约逻辑优先处理特定更新或客户。
• 尽管区块链当前存在交易限制，但通过批量交易和签名聚合等优化措施，可显著降低开销并提升可扩展性。