Anual Workshop February 5th, 2014

1. Anual Workshop February 5th, 2014

2. Anonymous yet reliable ePoll application Italo Dacosta SecAnon-DistriNet

3. Electronic Polls/Elections • Gathering opinions on a particular topic • Determining the most popular choice over a set of options • Typically targeted to a particular group of people

4. Problems • Generally identifiable • Integrity vs. anonymity • Users less motivated to freely participate and express opinions • Users cannot verify their votes • Need to trust the poll organizer • Difficult to restrict to a target group

5. Our Approach • Rely on anonymous credentials for ballot privacy • PriMan framework • Design verification capabilities for the bulletin board • Individual verifiability • Universal verifiability • Eligibility verifiability

6. Anonymous Credentials Authentication with a classical credential (X.509) Name: John Doe Gender: M Birthdate: 01/01/1970 Address: street 10, Leuven Zip code: 3000 Name: John Doe Gender: M Birthdate: 01/01/1970 Address: street 10, Leuven Zip code: 3000 Proof Sig Sig Authentication with anonymous credential (Idemix) Proof

7. Our Scenario • Low to medium scale polls/elections • Low to medium coercion • E.g., No high-stakes elections • Untrusted poll organizer • But trusted credential issuer • Voting over the Internet

8. Our ePoll Architecture Credential Issuance Issuer Server Voting Credential Storage & Retrieval ePoll Server Account Manager Server

9. ePoll Protocols • Registration protocol • Obtain ePoll anonymous credential from Issuer server • User validation (e.g. only one ePoll credential per user) • E.g., eID, workshop registration number • Storage & Retrieval protocol • ePoll credentials are securely stored in the Account Manager server • User authenticates to retrieve her credentials on her desktop computer or smartphone • Voting protocol • User selects a poll to participate • User uses her ePoll app and credential to participate in the poll • User can validate their vote was successfully submitted

10. Vote Verification • Poll Integrity Value (PIV) • PIVi= H(i | PIVi-1| datai) • Poll Authenticity Value (PAV) • Sign(SK, i | PID | PIVi) • Work in progress

11. Bulletin Board

12. Implementation • Java • PriMan framework • Mobile and Desktop client

13. ePoll Demonstrator

14. Questions?