Think of a voting token as a key a house and the ballot as the contents of the house. It is tempting to track ballots and voting tokens with place and time stamps, but that allows for matching who votes and what they voted for. However, the secrecy of the vote may need to be balanced with the need to avoid fraudulent ballots. Normally, you would match polling place attendance lists against votes cast. The transaction facility ensures that if the system fails for any reasons, at most, only one vote will be lost.
Encryption ensures votes remain secret.
The security levels help ensure only authorized personnel have access. What happens if the decrypting key is lost. Editorial By Reg. By now you must have gathered that this issue concerns automating the voting process. While the basic design of many aspects of an automated system are discussed here, a system design of the magnitude needed can not be really done in the space we have available here.