For some, the stock experience on smartphones is just not enough, and that's why many people turn to rooting and modding their devices so they may get some extra functionality and personalization capabilities they didn't otherwise have with stock. The only issue with this process on Sony's Xperia devices, is that it reportedly results in a loss of the DRM keys that Sony has developed into the device when the device's bootloader is unlocked, and since unlocking the bootloader is a process you need before you can root, losing the DRM keys is really not something you can avoid.
While this isn't necessarily the worst thing, losing the DRM keys seems to cause some of Sony's copyrighted device functions, like noise cancelling and the X-Reality software, to be removed. There have also been reports of the camera quality on devices like the Xperia Z3 dropping because of unlocked bootloaders. If you're someone that has unlocked the bootloader on your Xperia device, there is a handy little tutorial to restore the functions that are lost as a result of the lost DRM keys, so you can have those functions like noise canceling and the X-Reality software back. It does not however, as pointed out by the members over at XDA where these steps were posted, restore the DRM keys themselves.
The process isn't terribly difficult as it only involves flashing a file to your device through the custom recovery, with that said though you still want to make sure and read through everything on the original thread for this process. This ensures that you have the correct file and are flashing what you're supposed to be flashing. Thankfully it's less involved than actually rooting a device or throwing on a custom ROM which sometimes has multiple steps. If you have unlocked your bootloader and were looking for a way to get some of the Sony specific functions back that you lost, this should help you out. Keep in mind though that you're doing this at your own risk and any damage to your device is your own doing, as when messing with flashing files to your device nothing is ever certain. With that being said, many users have already reported this process has worked for them in the forum thread.