I use Bit Locker encryption on all of my Thumb drives that contain personal data.
Has anyone else of late, noticed the slow down of Bit Locker USB full encryption process. 7-8hrs to encrypt a Sandisk 128 GB Thumb drive is ridiculous.
USB2 or 3? What do you have set for cipher strength? The default was changed in 1511 to use XTS although I didn't notice it being slower, perhaps it is.
I don't have such large USB keys bit it does seem very slow - there is no point encrypting the whole volume if the drive is new or it has been encrypted before so you could consider that also.
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