Back when Android 5.0 was announced, Google revealed that it would require all devices running the upgraded OS to use full-disk encryption by default to protect users. However, it seems that Google has now reversed course on that decision and allowed several Lollipop devices to ignore this requirement.
As noted by Ars Technica, several Android devices—both new and old—that run the Lollipop software have decided to forgo encryption for some reason. This includes previously released devices that were upgraded to the new software such as the Moto G, and new devices that ship with Lollipop, like the more recent Moto E.
The Galaxy S6 demo units that members of the press have been trying at the MWC this year are reportedly not encrypted either, though we’ll have to wait and see if that will be true of the shipping models. As it turns out, Google has transitioned away from requiring encryption to simply “very strongly recommend[ing]” that it be enabled out-of-the-box.
Per the Android 5.0 Compatibility Definition:
9.9. Full-Disk Encryption
For devices supporting full-disk encryption, the full-disk encryption SHOULD be enabled all the time after the user has completed the out-of-box experience. While this requirement is stated as SHOULD for this version of the Android platform, it is very strongly RECOMMENDED as we expect this to change to MUST in the future versions of Android.
As you can see from the compatibility document, Google is not actually requiring handset makers to enable full-disk encryption on Lollipop, but says that it expects to update this policy in “future versions of Android.”
Why Google decided to make this change is a mystery, but as it stands, users who bought Lollipop devices expect (based on Google’s own announcement) that the device would be fully encrypted from day one should take some time to ensure that the setting is enabled on their phone.
To make sure that full-disk encryption is enabled on your Lollipop device, open the Settings app and navigate to the Security menu. From there, tap “Encrypt phone” to begin the process.