Masked Ballot Voting for Receipt-Free Online Elections

1. Masked Ballot Voting for Receipt-Free Online Elections • Sam Heinith, • David Humphrey, • and Maggie Watkins

2. Why Online Voting? • Quick election results • No paper ballot recounts • Less costly for the voter than mail-in elections • No long lines to vote • Faster than mailing in absentee ballots

3. Requirements For Secure Online Voting • Receipt Free • Untappable Channels • Individually Verifiable • Anonymous Channels • Universally Verifiable

4. How Masked Ballot Voting for Receipt-Free Online Elections Works • Three stages to an election • stage 1: Registration • stage 2: Voting • stage 3: Unmasking • Security • ElGamal Encryption ensures a vote cannot be • linked to a voter (secret ballots)

5. During an Election Public Registrar/ Authority Voter Private Bulletin Board

6. Stage 1: Registration Public Publish Public Key Registrar/ Authority Voter m, d m = unique mask Private V,〚m〛 d = security verifier Store Private Key Bulletin Board V = unique voter ID 〚m〛= encrypted mask

7. Stage 2: Voting Public Registrar/ Authority Voter Private 〚vote - m〛, p BulletinBoard 〚vote - m〛= masked and encrypted vote p = proof of plaintext knowledge

8. Stage 3: Unmasking Public Registrar/ Authority Voter Read from BB V,〚vote〛 Private vote Unencrypted Results to be counted BulletinBoard Election Results 〚vote〛= encrypted vote

9. ElGamal Encryption Example of homomorphic property of ElGamal: 〚vote - m〛= 〚vote〛-〚m〛 Decrypts to:vote - m • The Masked Ballot Voting scheme depends on a homomorphic encryption system because the masking and unmasking happens while the vote is still encrypted. • ElGamal is a Homomorphic encryption system. A homomorphic encryption system allows for performing operations on the cyphertext that predictably change the plaintext. 

10. Assumptions • Authority is not corrupt • Authority has plenty of processing power • Voters have little processing power • Untappable channel during registration • Voting is an atomic process

11. Sources • Wen, Roland, and Richard Buckland. "Masked Ballot Voting for Receipt-Free Online Elections." Lecture Notes in Computer Science, vol. 5767 (2009): pp. 18-36. • Schneier, Bruce. Applied Cryptography: Protocols, Algorithms, and Source Code in C. New York: Wiley, 1996. Print. (sited over 8,000 times according to Google Scholar)

12. Download Our Code! http://code.google.com/p/maskedballotvoting/

13. Demonstration

14. http://maskedballotvoting.googlecode.com/files/client.jar

15. Questions?