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 Go

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 it would get slower and slower. Anecdotally, I tried encrypting my HTC One M7 a few years ago for security, and I eventually I had to factory wipe the damn thing because the overhead 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 I was even presented with a lockscreen! The M7's specs were nothing to scoff at in 2013. Given the incredibly limited specs of Amazon's tablets, however, I would not be surprised if encrypting them could slow them down further to the point of being unusable. [0] http://arstechnica.com/gadgets/2015/03/google-quietly-backs-away-from-encrypting-new-lollipop-devices-by-default/ http://arstechnica.com/gadgets/2015/03/google-quietly-backs-... [1] http://www.androidpolice.com/2014/11/20/anandtech-posts-side-by-side-nand-performance-for-nexus-6-encrypted-vs-unencrypted-its-not-pretty/ http://www.androidpolice.com/2014/11/20/anandtech-posts-side...