Examining the value of SafetyNet Attestation as an Application Integrity Security Control

Google promotes the SafetyNet Attestation API as a tool to query and assess the integrity status of an Android device. The official documentation, leaves no doubt that the main purpose of the SafetyNet Attestation API is to provide device integrity information to the server counterpart of mobile applications. The server counterpart may choose to limit the functionalities available to an app, if it's running on a device with compromised integrity protections. However, in the past year CENSUS has performed a number of assessments to mobile apps where SafetyNet was also used as an application integrity security check. Furthermore, best practices documents such as ENISA's "Smartphone Secure Development Guidelines" document of December 2016, clearly propose the use of SafetyNet as a measure to check an app's integrity status (see page 23).

To the best of our knowledge, Google has not publicly released any detailed official documentation or recommended the use of the SafetyNet Attestation API for application integrity purposes.