How to Encrypt Your Android Phone (and Why You Might Want to)
Google introduced full-device encryption back in Android Gingerbread (2.3.x), but it has undergone some dramatic changes since then. On some higher-end handsets running Lollipop (5.x) and higher, it’s enabled out-of-the-box, while on some older or lower-end devices, you have to turn it on yourself.