Comment 9 for bug 437446

By the way, it seem that Grub2 1.97~beta4 (the version in 9.10 - currently up to 1.97~beta4-1ubuntu4.1) does support passwords, although not yet MD5-encrypted passwords - see https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/392158

See also http://grub.enbug.org/Authentication