[Linux-disciples] Creating an encrypted device

[Stephen R Laniel]

I'm following the directions here to make an encrypted
filesystem using dm-crypt:
http://shorl.com/hykekalodrigru

I don't want to create a new partition, or experiment on my
whole hard drive, so I created a new file with

dd if=/dev/zero of=cryptsys bs=4k count=1048576

I followed the directions for cryptsetup (which has
apparently become part of Debian since that article was
written), but it looks like it wants a block device;
cryptsys isn't one.

Yet ... I must be able to fake a block device out of this. I
suspect somehow I can use the loop device for this, but I've
only ever used the loop device while mounting over a
pre-existing device node; I've never used it to, say, create
a raw block device.

There must be some easy way to do what I want, right?

-- 
Stephen R. Laniel
steve at laniels.org
+(617) 308-5571
http://laniels.org/