Some Consequences of Paper Fingerprinting for Elections

Recent research has demonstrated that individual pieces of paper can be fingerprinted and re-identified later at low cost, using commodity scanners. The authors consider the consequences of this fact for electronic voting. The most obvious consequence is negative: the ability to fingerprint paper endangers the secrecy of ballots in any system that keeps paper records of individual ballots, including standard optical scan and DRE-VVPAT systems. They characterize the resulting risks and discuss when and how they can be mitigated.