Encrypted swap partition on removeable device

[Paddy Landau]

If installing Ubuntu (in this case 11.04) on a removable USB hard drive with an encrypted home folder, it (correctly) encrypts the swap partition.

However, if the swap is on (say) the first partition, it could -- depending on the computer you are booting from and whether or not other devices are plugged in -- be any of /dev/sdb1, /dev/sdc1, /dev/sdd1, ...

But the entry in /etc/crypttab gives the device as /dev/sdd1 (on my setup, anyway).

cryptswap1  /dev/sdd1  /dev/urandom  swap,cipher=aes-cbc-essiv:sha256

I need crypttab to be more flexible. Is it possible, e.g. to use UUID? (I am not sure if an encrypted partition can have a UUID.)

EDIT: I have just discovered that using an encrypted partition on a removable device can lead to catastrophic data loss if you do not carefully adjust the booting sequence as described in Arch Linux's wiki. Oops!

I still do not know how to get the UUID from an encrypted partition.