[monster_truck]

Have you actually compared the random data that various tools write to a disk to encrypted files? Load up binwalk and give it a rip, you will be surprised by how distinct the entropy graph is between the two

[ThePowerOfFuet]

What you propose ("the random data that various tools write to disk") is not _random data_.

Compare the entropy graph of /dev/random against a LUKS volume with a decrypted header, and you will see no difference.

[ThePowerOfFuet]

s/decrypted/detached/