gentoo problem:
icebird ~ # mount -t reiserfs /dev/hdc1 /secure/ -o loop,encryption=XXX Password: Error: Password must be at least 20 characters.
Just recompile:
ACCEPT_KEYWORDS="~x86" emerge "=util-linux-2.12i-r1"
I think this should only be a temporary solution. rebuild your encrypted partition with a correct password!
Perhaps a interesting link:
http://bugs.gentoo.org/show_bug.cgi?id=107680#c20