We propose a holistic methodology for designing automotivesystems that consider security a central concern at every design stage.During the concept design, we model the system architecture and definethe security attributes of its components. We perform threat analysis onthe system model to identify structural security issues. From that analysis,we derive attack trees that define recipes describing steps to successfullyattack the system's assets and propose threat prevention measures.The attack tree allows us to derive a verification and validation (V&V)plan, which prioritizes the testing effort. In particular, we advocate usinglearning for testing approaches for the black-box components. It consistsof inferring a finite state model of the black-box component from its executiontraces. This model can then be used to generate new relevanttests, model check it against requirements, and compare two differentimplementations of the same protocol. We illustrate the methodologywith an automotive infotainment system example. Using the advocated approach, we could also document unexpected and potentially criticalbehavior in our example systems.
翻译:我们提出了一种整体性的方法论,用于设计将安全性作为每个设计阶段核心考量的汽车系统。在概念设计阶段,我们对系统架构进行建模,并定义各组件的安全属性。我们通过对系统模型进行威胁分析,以识别结构性的安全问题。根据该分析,我们推导出攻击树,这些攻击树定义了成功攻击系统资产所需步骤的详细说明,并提出了威胁防范措施。攻击树使我们能够推导出验证和确认计划,该计划对测试工作进行了优先级排序。特别是,我们主张针对黑盒组件采用基于学习的测试方法。该方法包括从黑盒组件的执行轨迹中推断出其有限状态模型。然后,该模型可用于生成新的相关测试,对需求进行模型检查,并比较同一协议的两种不同实现。我们通过一个车载信息娱乐系统示例来说明该方法。通过采用所倡导的方法,我们还在示例系统中记录到了意外且可能关键的行为。