What's listed in the BINARIES section in the respective mkinitcpio.conf files of your Obarun & Arch Live systems?
If nothing is listed in the Obarun mkinitcpio.conf, try adding
/usr/bin/cryptsetup
and maybe also
/usr/bin/dmsetup /usr/bin/lvm
if you're using lvm2 in conjunction with your cryptsetup.