SchrodinText: Strong Protection of Sensitive Textual Content of Mobile Applications Ardalan Amiri Sani Computer Science Department University of California, Irvine
[email protected] Abstract Keywords Many mobile applications deliver and show sensitive and Text protection; Mobile devices; UI safety; TrustZone; Vir- private textual content to users including messages, social tualization network posts, account information, and verification codes. All such textual content must only be displayed to the user 1. INTRODUCTION but must be strongly protected from unauthorized access There are millions of mobile applications today. The tex- in the device. Unfortunately, this is not the case in mobile tual content that many of these applications show to the devices today: malware that can compromise the operating user in their UI can contain extremely sensitive and pri- system, e.g., gain root or kernel privileges, can easily access vate information, such as social security number, bank ac- textual content of other applications. count information, private messages, passwords (in a pass- In this paper, we present SchrodinText, a system solution word vault), and verification codes used for two-factor au- for strongly protecting the confidentiality of application's se- thentication. Such content must only be displayed to the user lected UI textual content from a fully compromised operat- but must be otherwise protected against unauthorized access ing system. SchrodinText leverages a novel security monitor by malware. Indeed, Zhou et al. found 644 malware samples based on two hardware features on modern ARM processors: (in 27 families) that harvest \user's information, including virtualization hardware and TrustZone. Our key contribu- user accounts and short messages stored on the phones" [54].