Eh. I see what you did there. :]

Nobody can see the ballot being deposited and stored.

To assure transparency, you would have to make all the process public, including the installation and configuration of the servers involved.
Plus, you should educate each citizen enough that he or she can be convinced that the voting process is safe and fair. And I said convinced, as in : "I know it works", not persuaded as in : "I'm sure some people know it works and everybody seems to agree, so I'm OK with that".