If it's only personally verifiable with 'something you know' (by being present, see my other post here) would that suffice? You'd have vote verification (that you voted, not how), the system would know your list but not who you chose, but you could check the list was recorded - you could still lie about who you voted for, just as you can now.
(This is not a working, nor complete idea, I'm scanning around for inputs. Thanks.)
