Post

First, this is really unfortunate, and I feel really bad. Sure, you can say "the trustee should have saved their secret key", but ultimately, as a system designer, I want my systems to be resilient to human mistakes. To be human is to err. Although, it's really hard to strike the right balance.

If you want voter privacy, even from me, the administrator of the Helios server, you need to use strong encryption on the ballots – in fact you need a special form of encryption that allows for accumulating votes under the covers of encryption.

And then you need to manage how the decryption of the tally is performed, and the only way we know how to do that reasonably well is by having a set of trustees where no single individual can go rogue and break privacy. But there's a very specific design tradeoff here.