I believe that the only way that online or electronic voting could work would be as an freely distributed "open source" community built & tested solution. If open source is secure enough to run the Whitehouse website it is likely secure enough to manage recording a vote.
Maybe we could engineer a situation where we use thin virtual clients from a master server and the actual "complete operating system" of the voting device could be imaged or have a current snapshot stored on the same media as the vote reciept itself for possible later verification or even independent verification on the spot by interested code developers.