Sometimes generating pseudo-random data is desirable in order to sidestep
caching or dedup mechanisms when measuring throughput. Lots of pseudo-random
data can be generated in an extremely fast manner by AES-encrypting /dev/zero
with a random key:

	# pv </dev/zero | openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64)" -nosalt >/dev/null

Roughly an order of magnitude faster that reading from /dev/urandom on my box,
YMMV.

In particular, if you want to generated a specified amount of data:

	# pv </dev/zero | openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64)" -nosalt | dd bs=16M count=1000 iflag=fullblock >dev/null

In this case, don't forget the 'iflag=fullblock' argument to avoid buffer underruns.

Update: Use a variant of this command to do wicked fast & easy symmetric encryption:

        # openssl aes-256-cbc -a -salt -pbkdf2 <some.input >some.output.enc

And decryption:

	# openssl aes-256-cbc -d -a -pbkdf2 <some.input.enc >some.output

Openssl will ask for a passphrase somehow, but it's not entirely clear how the
password is received in a manner than it is separate from the rest of stdin.
TBD.