Mutent: Dynamic android intent protection with ownership-based key distribution and security contracts

Intents are the plain-text based message object used for ICC by the Android framework. Hence the framework essentially lacks an inbuilt security mechanism to protect the visibility, accessibility, and integrity of Intent's data that facilitates adversaries to intercept or manipulate the data. In this work, we investigate the Intent protection mechanism and propose a security-enhanced Intent library µTent that allows Android apps to securely exchange sensitive data during ICC. Differently from the existing mechanism, µTent provides accessibility and visibility of Intent data by validating the receiver's capability and provides integrity by using encryption and the Arc security contract code. Especially, ICC is initiated by exchanging µTent and follows a novel ownership-based key distribution model, that restricts the malware apps without permission from deciphering data. Through the evaluation, we show that µTent can improve the security for popular Android apps with minimal performance overheads, demonstrated using F-Droid apps.