Lockdown: A Safe and Practical Environment for Security Applications (CMU-CyLab-09-011)

We describe, build, and evaluate Lockdown, a system that significantly increases the level of security for online transactions, even on a platform infested with malicious code. Lockdown provides the user with a highly-protected, yet also highly-constrained trusted environment for performing online transactions, as well as a high-performance, general-purpose environment for all other (non-security-sensitive) applications. A simple, user-friendly external interface allows the user to securely learn which environment is active and easily switch between them. We focus on making Lockdown deployable and usable today. Lockdown works with both Windows and Linux, and provides immediate improvements to security-sensitive tasks while imposing, on average, only 3% memory overhead and 2–7% storage overhead on non-security-related tasks.