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I've encrypted my Transcend Jetflash flash drive (16 GB, USB2, ext2). Before the operation, the flash drive's speed was:
# dd if=/dev/zero of=/media/JetFlash/file bs=1M count=256
Results with: 26,5 s, 10,1 Mb/s
Then I encrypted it:
# losetup -e AES128 /dev/loop1 /dev/sdb
# mkfs -t ext2 /dev/loop1
# losetup -d /dev/loop1
# mkdir /mnt/tmp
# mount /dev/sdb -o loop=/dev/loop1,encryption=AES128 /mnt/tmp -t ext2
# losetup -e AES128 /dev/loop1 /dev/sdb
And I've executed the same command:
# dd if=/dev/zero of=/mnt/tmp/file bs=1M count=256
Results with: 11,98 s, 22,4 Mb/s
For AES256 the result was: 12,83 s, 20,9 Mb/s
Can somebody explain what's happening? Why does an encrypted flash drive works twice as fast?
I think that's not a programming related question and therefore the wrong place to ask. – None – 2011-06-23T10:05:34.167