Ginseng: Keeping Secrets in Registers When You Distrust the Operating System

Many mobile and embedded apps possess sensitive data, or secrets. Trusting the operating system (OS), they often keep their secrets in the memory. Recent incidents have shown that the memory is not necessarily secure because the OS can be compromised due to inevitable vulnerabilities resulting from its sheer size and complexity. Existing solutions protect sensitive data against an untrusted OS by running app logic in the Secure world, a Trusted Execution Environment (TEE) supported by the ARM TrustZone technology. Because app logic increases the attack surface of their TEE, these solutions do not work for third-party apps.