CAREER: Towards Trustworthy Operating Systems

操作系统是计算机系统的关键软件，它管理硬件和软件资源，并为计算机程序提供必要的服务。它对整个系统的安全起着至关重要的作用。不幸的是，现代操作系统往往充斥着数百万行源代码，严重的漏洞经常被发现和利用。研究人员已经提出了基于“下一层”方法的各种新颖的解决方案，其中更有特权的软件组件（即，管理程序）被引入来监视和/或调节操作系统？的行为。然而，现代虚拟机管理程序的庞大可信计算基础以及最近针对它们的攻击使这种方法受到质疑。该项目旨在开发一种系统化的方法，通过实现操作系统的自我防御来提高操作系统的可信度，而不诉诸其他可能易受攻击的软件层。该项目的目标通过三个关键步骤实现：首先，该项目开发一个内核级安全飞地，为其他安全系统和机制提供可信的安全执行环境。其次，基于飞地提供的强隔离性，设计并实现了几种操作系统内核的自我防御技术。第三，冷启动攻击是一种强大的物理攻击，可以从丢失或被盗计算机（包括移动的设备）的物理内存中提取敏感信息。它已成为企业和政府的主要安全问题。本项目研究了一个全面的防御冷启动攻击通过加密商品硬件平台上的敏感程序的整个内存。该项目的结果可以大大提高我们对恶意和隐形内核级恶意软件和冷启动攻击的防御能力，从而显着提高计算机系统的可信度。研究成果通过出版物、发布开发的工具以及纳入研究生和本科生教育活动进行传播。

An operating system is the key software of a computer system that manages the hardware and software resources and provides essential services to computer programs. It plays a critical role in the security of the whole system. Unfortunately, modern operating systems are often bloated with millions of lines of source code, and serious vulnerabilities are routinely being discovered and exploited from them. Researchers have proposed various novel solutions based on the "one-layer-below" approach, in which a more privileged software component (i.e., a hypervisor) is introduced to monitor and/or regulate the operating system?s behavior. However, the large trusted computing base of modern hypervisors and the recent attacks against them put this approach into question. This project aims at developing a systematic approach to improve the trustworthiness of operating systems by enabling their self-defense, without resorting to other software layers that may be vulnerable themselves.The goal of this project is being achieved in three key steps: first, the project develops a kernel-level security enclave that will provide a trusted, secure execution environment for other security systems and mechanisms. Second, based on the strong isolation provided by the enclave, the researchers design and implement several self-defense techniques for operating system kernels. Third, a cold-boot attack is a powerful physical attack that can extract sensitive information from the physical memory of a lost or stolen computer (including mobile devices). It has become a major security concern for corporations and governments. This project investigates a comprehensive defense against cold-boot attacks by encrypting the whole memory of a sensitive program on commodity hardware platforms. The results from this project could substantially improve our defensive capabilities against malicious and stealthy kernel-level malware and cold-boot attacks, and thus significantly improving the trustworthiness of computer systems. Research results are disseminated through publications, releasing of the tools developed, and integrating into the educational activities at both the graduate and undergraduate levels.