Google has stopped requiring Lollipop devices to be encrypted by default. Google made waves last year when it announced that devices running Android 5.0 Lollipop would require full-disk encryption by default. The move was seen as an added security measure after reports of government spying on American citizens. Unfortunately, however, the requirement came with some unwanted side effects, notably in the form of performance issues in devices such as the Nexus 6.
The full-disk encryption caused unexplained slowdowns in all sorts of tasks, and particularly became a problem with the Nexus 6, which is one of the best-specced phones on the market. Users didn’t expect the phone to have any performance problems, and when the slowdowns were found, they were traced back to the required full-disk encryption.
The default encryption had the potential to be much worse in mid-range and entry-level devices, so Google made the wise move to relax the requirements. A precise date of the change isn’t known, but it was recently found in the Lollipop hardware requirements, which were published in January, a couple of months after Lollipop’s release. The change wasn’t noticed until Ars Technica noticed that the Moto E (2nd Gen) didn’t have the encryption by default. Doing some more investigating, they also found that the just-announced Galaxy S6 left encryption off, as well as many older devices.
Google’s guidelines state that while it strongly recommends default encryption, it won’t require it in Lollipop. They do, however, indicate that a future version of Android will require encryption. Much as we support encryption, devices simply weren’t designed to handle full-disk encryption. Taking away the requirement for the time being allows manufacturers to create devices with faster memory and chips that are optimized for full-disk encryption, which should eliminate the problems that encryption currently poses.