Disk Encryption and the Acer Aspire One

The Acer Aspire One 150l comes with a seagate ST9120817AS sata drive.
But unlike the Via C7, the Intel Atom has nothing like padlock.

You can however modprobe

twofish_i586
aes_i586


I forced the intel rng to load after an otr request locked my book for several minutes… haven’t tested yet if it helps.

intel_rng no_fwh_detect=-1


The following benchmarks were not done with great care, they are by no means repsrentative. The system wasn’t in single mode and the tests were only repeated once or twice.

Note: Today, without changing really anything, the pure lvm test get 55mb/s buffered disks reads and the 128bit twofish benchmark 11mb/s

unencryped logical volume

# hdparm -tT /dev/acer150l/home2

/dev/acer150l/home2:
Timing cached reads: 1156 MB in 2.00 seconds = 577.59 MB/sec
Timing buffered disk reads: 110 MB in 3.04 seconds = 36.19 MB/sec


AES 256

# cryptsetup --verbose --verify-passphrase -c aes-cbc-essiv:sha256 --size 256 luksFormat /dev/acer150l/home2
# cryptsetup luksOpen /dev/acer150l/home2 user
# hdparm -tT /dev/mapper/user

/dev/mapper/user:
Timing cached reads: 1178 MB in 2.00 seconds = 588.92 MB/sec
Timing buffered disk reads: 34 MB in 3.13 seconds = 10.86 MB/sec


AES 128

# cryptsetup --verbose --verify-passphrase -c aes-cbc-essiv:sha256 --size 128 luksFormat /dev/acer150l/home2

Timing cached reads: 1118 MB in 2.00 seconds = 559.25 MB/sec
Timing buffered disk reads: 66 MB in 3.04 seconds = 21.69 MB/sec


Twofish 128

# cryptsetup --verbose --verify-passphrase -c twofish-cbc-essiv:sha256 --size 128 luksFormat /dev/acer150l/home2

/dev/mapper/user:
Timing cached reads: 1116 MB in 2.00 seconds = 558.19 MB/sec
Timing buffered disk reads: 34 MB in 3.16 seconds = 10.77 MB/sec


Twofish 256

# cryptsetup --verbose --verify-passphrase -c twofish-cbc-essiv:sha256 --size 256 luksFormat /dev/acer150l/home2

/dev/mapper/user:
Timing cached reads: 1124 MB in 2.00 seconds = 562.16 MB/sec
Timing buffered disk reads: 34 MB in 3.14 seconds = 10.83 MB/sec