blueser writes "From Nov 10th to Nov 13th the Brazilian Government hosted a public hacking contest to test the robustness of its voting machines. 38 participants from private and public IT companies (including the Brazilian Federal Police) were divided into 9 teams, which tried several different approaches to try to tamper with the software installed on the machines, and even to physically interfere in other stages of the process. All attempts (aside from a minor one which would not compromise the overall results) failed, and observations from the participants and neutral observers will be taken into account to improve the process even further. Here is the official announcement for the contest (Google translation; Portuguese original). A summary of the results is available in the Brazilian press (original). Brazilian voting machines use Linux."
US voting officials ought to be envious of their Brazilian counterparts, or ashamed, or both. Perhaps this MIT-developed cryptographic voting system
offers a way forward.