Voting systems have a number of key requirements. To prevent bribes or coercion, the vote has to be anonymous and the voter must not be able to prove his vote. On the other hand, it must be possible to verify that each cast vote has been counted correctly. Finally, the whole process should be transparent and understandable for every interested voter.

These requirements can be easily fulfilled with a well designed paper ballot system. I don't see any chance of doing the same with anything computerized.