Secret Voting

1
Secret Voting

• What makes
• a secret vote secret?

2
Voting Goals

• Need to record who votedonly eligible voters can
  vote, nobody votes twice
• Need to record the votesto determine a winner
• but
• May NOT know who voted whatthe essence of a
  secrete vote

3
Step 1 Submit your Ballot

• Signature on envelope certifies who you are
• Your name can be checked against list of eligible
  voters

4
Step 2 Separate Envelope
5
Step 3 Tabulate Results

• Voter List
• Bert Wachsmuth
• Joe Student
• Jane Faculty
• Contains list of who voted

• Votes List
• George Bush 2 votes
• Al Gore 3 votes
• Contains a list or summary of anonymous votes

6
Cheating

• Prevent eligible voters from voting
• Vote without being eligible
• Vote more than once
• Invalidate valid votes or validate invalid votes
• Learn who voted what
• (active) observe during voting process
• (passive) maintain relationship between voters
  and votes
• do not separate voter name from vote
• keep voter list and votes list in same order