End-to-End Verifiable Elections with DEMOS                                                                                        
Every paper ballot of DEMOS consists of two sheets, A and B.


The voter chooses one sheet to use for voting and keeps the other sheet for verifiability purposes. 

The important characteristics in each sheet are shown in the following picture.

The voter votes using:
  • either the digital ballot box (a device that reads the paper ballot, e.g. a tablet)
  • or via the internet in a web site; the URL is written on both sheets of the ballot
Voting takes place by submitting the vote code that corresponds to the candidate of the voter's choice. If voting is successful, the system responds with the vote code receipt which is unique for every sheet and every vote code.

After voting has ended, the results are posted to the audit bulletin board; the URL of the bulletin board is written on both sheets of the ballot.  

To audit your vote,  you have to type the serial number of your ballot at the "Audit" tab.

Next, you have to do the following three steps:

1. Recorded-as-cast verification. At the tab that corresponds to the sheet that you used to vote (A or B), verify that a "check" symbol appears next to the vote code you submitted. 

2. Verification of correct vote-code/candidate correspondence. At the tab that corresponds to the sheet that you did NOT use to vote, verify that the vote-code/candidate correspondence is the same as the one in the said sheet of your ballot.

3. Cryptographic elements verification. The graphical environment of DEMOS corresponds to a table of cryptographic objects that must also be verified. You may do this using your browser by pressing the button "Verify cryptographic elements". Alternative ways of verifying the cryptographic elements are also available.

In our VIDEOS page you can find a video describing the above procedures.