In code, you have no insight into what actually happens.
trivia: did you know that a tear in any of the pages of your passport renders it invalid?
In any system, I suspect it is possible. There are strategies that allow doing private set intersections (or similar): https://en.wikipedia.org/wiki/Private_set_intersection (i.e. a set with one member is "you", and you can check to see if you're in that 764, without knowing who the others are)
I'm not sure what strategies would also allow you to not reveal to the vote collectors where your vote went, but there might be something.
That still leaves tons of other technical problems to address, like security of mail-ballots / absentee ballots, the security of ballot boxes used for early voting (because you probably cannot run the above manual partial audit due to then having nightly results available to the public; or maybe you accept that), etc.
Your ID card contains a private key, you use that key to sign a transaction. It doesn't matter that machine you are running on is compromised as these details can be verified at a later date.
Example A: You vote for candidate A, but software changes to candidate B and software displays that you voted for candidate A. At any later time you can check with an independent device and look at the transaction finding out that it was altered with and retract your vote / change it.
Example B: How do you know your vote was counted? Publish a hash and the signature of every vote, recompute the final tally and compare with all the votes. If your vote is not in the final tally the hash will be different and you can visibly see your vote in the dataset as every transaction is published. To preserve privacy each round has a number, private key + number -> new key so each fingerprint will be unique between votes.
I mean that's too abstract and philosophical of a problem when talking about voting machines/software: there are much more prevalent and concrete risks including but not limited to APT-grade breach/espionage if your country is important enough, and the various other issues (some in your comment itself).
samat•29m ago
jeff_vader•19m ago
> The intention behind this repository is to make source code of the Estonian online voting system available for public review.
> The repository is not used for active development, but will be kept up to date, so the code that can be found here is the code that is used for election.
piiritaja•17m ago
The repository is not used for active development, but will be kept up to date, so the code that can be found here is the code that is used for election. As the voting system used for legally binding elections must strictly follow the legislation, the actual development of Estonian I-voting system and I-vote verification application is supervised by State Electoral Office of Estonia. Please refer to www.valimised.ee for further information.