Amazon confirms it has dropped device encryption support for its Fire Tablets
Since this is now front page and last night's thread on this has fallen off, I'll repost what I said there, supporting the theory that encryption might actually have been turned off for performance:People unfamiliar with full-device encryption on Android devices need to be aware of the following: until Marshmallow, it was SLOW. It was so bad that while Google recommended turning on encryption by default on Lollipop, they had to back off of the recommendation because full-disk encryption made the devices run like crap. [0] The reason suspected for this is that up to and including Lollipop, Android handsets did not support hardware-backed encryption/decryption, which meant it all had to be done in software.[1] This had the end result of putting huge overhead onto the device once FDE was turned on, and over time its performance would continue to degrade. Anecdotally, I tried encrypting my HTC One M7 a few years ago when it was my daily driver, and I eventually I had to factory wipe the damn thing to turn it off. The overhead with encryption on got so bad that I would periodically turn on the screen, and it would take so long for the phone to respond that the auto-idle would turn the screen back off before I was even presented with a lockscreen!The M7's specs were top shelf in 2013. Given the limited specs of Amazon's cheaper tablets, I would not be surprised if encrypting them could slow them down further to the point of being unusable.[0] http://www.androidpolice.com/2014/11/20/anandtech-posts-side...
[1] http://www.androidpolice.com/2014/11/20/anandtech-posts-side....EDIT: Removed the aside, since I was mistaken that the Kindle reader OS's were affected.