Over-the-Air (OTA) software updates are becoming essential for electric/electronic vehicle architectures in order to reduce recalls amid the increasing software bugs and vulnerabilities. Current OTA update architectures rely heavily on direct cellular repository-to-vehicle links, which makes the repository a communication bottleneck, and increases the cellular bandwidth utilization cost as well as the software download latency. In this paper, we introduce ScalOTA, an end-to-end scalable OTA software update architecture and secure protocol for modern vehicles. For the first time, we propose using a network of update stations, as part of Electric Vehicle charging stations, to boost the download speed through these stations, and reduce the cellular bandwidth overhead significantly. Our formalized OTA update protocol ensures proven end-to-end chain-of-trust including all stakeholders: manufacturer, suppliers, update stations, and all layers of in-vehicle Electric Control Units (ECUs). The empirical evaluation shows that ScalOTA reduces the bandwidth utilization and download latency up to an order of magnitude compared with current OTA update systems.

翻译：空中软件更新对于电动/电子车辆架构正变得不可或缺，以应对日益增多的软件漏洞与缺陷、减少召回。当前空中更新架构严重依赖蜂窝网络从存储库到车辆的直接链路，这使得存储库成为通信瓶颈，并增加了蜂窝带宽使用成本及软件下载延迟。本文提出ScalOTA，一种面向现代车辆的端到端可扩展空中软件更新架构及安全协议。我们首次提出利用充电站网络（作为电动汽车充电基础设施的一部分）通过站点提升下载速度，并显著降低蜂窝带宽开销。所形式化的更新协议确保了包含所有参与方（制造商、供应商、更新站点及车载电子控制单元各层级）的可证端到端信任链。实验评估表明，与现有空中更新系统相比，ScalOTA能将带宽使用率和下载延迟降低至十分之一量级。