Electronic voting system based on "Zeus" implementation created by GRNET team, that was made from an open-source project Helios. Vote with one or more ballots, with mathematically certified credibility. Multiple ballot items are supported and electoral systems, such as multiple choice questions, voting by different ballot per combination, and ballot papers (STV). «Zeus» was originally based on Helios and maintains the general approach, but has since followed its own its course. It has served more than 250 electronic ballots and 35,000 voters for Greek Universities and other bodies.
"The Digital Kalpi Zeus" is an information system for inviolable conduct of secret ballots by purely electronic way. Both the preparation of the vote by the current authority and and the submission of the vote by the voters, takes place remotely via Web.
The voting process, briefly:
Communication of authorities and voters with the information system "Zeus" is done through a simple program web browser while protected just like online financial transactions.
The integrity of the ballot is mathematically verifiable by each through the use of cryptography, and without any insult of secrecy.
The secrecy of the ballot is the responsibility of the electoral commission, and is practically guaranteed as long as there is one and only an honest member of the committee.
The voter receives a message in his e-mail when the vote is ready to begin. The message informs him for the exact date and time of its start and end voting. For each change that is made, it also receives a new message.
The message contains a personal and confidential link on the site "Zeus". The process Voting begins by following this link, if Of course, the vote is already underway. Otherwise the voter is informed accordingly.
An introductory note appears on the voter's screen describes the voting process. The process consists from two steps, the selection of candidates on the ballot , and the submission of the ballot.
In the selection step, a representation appears on the screen a ballot, as well as the necessary information and instructions. The voter interactively composes her ballot his choice.
When the selection process is complete, the voter proceeds to submit the ballot. The selected ballot encrypted on the local computer of the voter and then submitted over the network to the "Zeus". The system issues digital proof of voter registration in the form of a simple text file, which the voter owes to keep, as it is necessary for the submission and processing of any objections.
The members of the electoral commission in the "Zeus" are the keyboardists of the vote. The members of the committee receive special cryptographic keys, the Codes Voting . These codes are all necessary for conducting the vote as well as decrypting them results. If even one is lost, the vote will not can be completed, as it will be impossible to decryption of ballots. Every member of the electorate committee is responsible for safeguarding its own Code, while the "Zeus" it also has a Code for each vote, as if he were a member of the committee.
The first act of any member of the committee is to enter on the voting site, to produce a new Code Vote, and then submit his public part in the "Zeus" Voting can begin only when all members of the committee have performed and confirmed this step.
After the end of the voting, the decryption of the ballots it is impossible without all Voting Codes. Each member of the executive committee is connected to the system "Zeus" to provide cryptographic data that are necessary to extract their contents ballots. The provision of cryptographic data does not insults the secrecy of the ballot.
In order to ensure the secrecy of the ballot when complete the voting process, and before the counting of votes, an intermediate stage of mixing is introduced of ballots. At this stage the already encrypted, by voters, ballots, are encrypted in a special way from new from the system "Zeus", so that it is no longer recognizable and randomly rearranged. At the end of the process mixing we have a set of ballots which when decrypted will have the same contents as the original, but it is impossible to connect them to the users who submitted them. With the care of the supervisory committee, computers outside it system "Zeus" can participate in the mixing without risk of altering the process. As with the committee, just one honest participant in the mix is enough to make sure the secrecy.
The "Zeus" is based on implementation electronic voting as described at home publication of system Helios . In the In this system, voters submit encrypted ballots which are mixed to maintain their anonymity voters, a sequence that forms the basis of the system "Zeus". In later Helios implementations, as in its current implementation, this was abandoned approach and the stage of mixing them was omitted ballots, as this is not necessary in cases where ballot decryption is not even required export the results. Such cases are electoral contests where voters choose candidates (for example with a cross) and the candidates are elected with the greater number of crosses (approval voting). Then export them results can be done with cryptographic (homomorphic) operations on encrypted ballots. This is not possible in cases where full structure knowledge is required of the ballot and not of the independent options in it, such as for example in the classification voting system ( Single Transferable Vote ).