How to make use of ARM Trust Zone in Android Application

Question

I am devlopeing some application wherein i have to store the keys in secure manner and do some cryptographic operation on it.

Answer 1

You can't use it directly. You need to develop (or buy) a trusted application and then have your app talk to it through the secure API it provides. This may or may not be usable on all devices, so unless you control the device and/or firmware, it is not guaranteed that you can use it all.

The system keystore on some devices already uses hardware-backed storage for RSA keys (Nexus 7 for example), but it is not standard and some devices only have a software implementation.

Answer 2

If you are targeting the Western World, where Samsung is by far the dominant player, you can make use of their API for Trust Zone: https://developer.samsung.com/teegris

Answer 3

2019 update:

You still can't use it directly. You should use Google APIs for Android security, some of which may or may not use TrustZone. It is a security tech aimed at device and OS manufacturers, not app developers.

You can read more on the topic here:

ARM TrustZone on Android