Understanding Helios vote encryption

[Matías Lermanda]

Hello,

I'd like to get a better understanding of how Helios encrypts the election tally and the individual votes.

I am using password authentication for the voters (not google/facebook/etc.).

To my knowledge, Helios creates a public and private key for each election (for each trustee I think?), then sends an email to each voter with their username (provided in the uploaded .csv) and a randomly generated password, along with the link to vote.

The user authenticates and then votes in a process that can be entirely offline, the vote is then encrypted with the public key of the election (the key of each of the trustees I'm guessing) and the voter can then choose to cast it.

At the end of the election, votes are tallied using the properties of homomorphic encryption along with some very clever math without the need to decrypt each vote individually.

Is my thought process correct? Is the vote encrypted only with the public key (or maybe keys if there's more than one trustee) of the election? Are the votes tallied in the way I described?

I've got no problem if the answer to all my questions is something along the lines of "just read the faq/about/documentation", but in that case I'd appreciate a link to where I can get the information.

Thanks in advance for any answer I can get.