Individual verification with POLYAS

POLYAS offers various verification methods so that, after voting, your eligible voters can check that their completed ballot arrived in the digital ballot box as intended. These methods can be booked as modules depending on the assessment of security risks around a digital election.

Verification codes for checking your own vote

Individual checks by using verification codes are available with POLYAS Live Voting and also with the online elections. This allows eligible voters to check whether their vote is listed in the election results as they intended (Tallied-as-Cast Verification). This verification method alone does not offer comprehensive protection against every conceivable risk and is most suitable if the election procedure is trusted in principle.

How verification codes work
After casting their vote, eligible voters receive a downloadable receipt that contains the multi-digit code (signed hash) for their encrypted ballot. This code can be used to identify the ballot in the ballot box; each verification code exists once only. However, nobody else can know who this ballot paper is assigned to, so voting secrecy is preserved.

After the election, the election management publishes a list of all of the codes with their associated votes. Eligible voters can use this list to check whether their code is included in the list and whether the associated voting decision is listed correctly.

Alternatively, the election management is also free to publish just the list of verification codes. Eligible voters can check whether their code appears in the list and thus know that their vote was received.

Individual verification using a second device

This involves using a second device to check whether the vote was cast correctly. In this way, it is possible to verify that the first device was free of malware and that the vote cast in the POLYAS ballot box corresponds to the voter’s decision.

The application is provided and operated by POLYAS. For elections with very high security requirements, this can be handled by an independent service provider. This method of verification is currently available only for POLYAS Online Voting.

How the second device works
The device used for voting shows each eligible voter an individual QR code after they have cast their vote. This QR code contains encrypted proof that the ballot paper was transferred to the ballot box correctly.
The eligible voter can now use a second device (e.g. a smartphone) to scan the QR code and access a POLYAS web app, where they can use their login data to authenticate themselves again. After successful authentication in the web app, the proof of voting is now decoded and the voter is shown their selection (ballot paper in the ballot box) as plain text.

To prevent the displayed ballot paper from being used as a receipt for vote buying, it can be modified in the display on the second device. Subsequent modification does not affect the actual ballot cast in the ballot box. The verification protocol of this method is structured in such a way that the voting secrecy is maintained unless a voter passes on their personal login data to third parties.

Outlook on individual verification with POLYAS

We want to strengthen trust in the integrity of digital voting and elections. To this end, we are developing cryptographic proof and security mechanisms that minimize all of the risks of voting and make all processes verifiable. Depending on the analyzed security level of a digital vote, security measures can be combined and booked as modules.