Software services have become an integral part of our daily life. Cyber-attacks have thus become a problem of increasing importance not only for the IT industry, but for society at large. A way to contain cyber-attacks is to guarantee the integrity of IT systems at run-time. Put differently, it is safe to assume that any complex software is compromised. The problem is then to monitor and contain it when it executes in order to protect sensitive data and other sensitive assets. To really have an impact, any solution to this problem should be integrated in commodity operating systems.
In this thesis we introduce run-time security primitives that enable a number of trusted services in the context of Linux. These primitives mediate any action involving sensitive data or sensitive assets in order to guarantee their integrity and confidentiality. We introduce a general mechanism to protect sensitive assets at run-time that we denote split-enforcement, and provide an implementation for ARM-powered devices using ARM TrustZone security extensions. We design, build, and evaluate a prototype Trusted Cell that provides trusted services. We also present the first generic TrustZone driver in the Linux operating system. We are in the process of making this driver part of the mainline Linux kernel.