Install

Installing zeus-client tool should be as simple as

$ pip install zeus-client
$ zeus-client --help

Remote mix

The mix command can be used for elections with remote mixing enabled during initial election parametrization. Once election voting closes and zeus completes the first mix of encrypted ballots, Zeus produces the election remote mix URL to the election administrator. The URL can be shared across the preferred set of participants as required by the election process. Each participant takes part to the election mix as follows:

- Download previously set of mixed ciphers
- Generate a new mix
- Upload the new ballot mix (will be used as input for the next mix)

zeus-client automatically takes care of all of the above steps:

$ zeus-client mix <election-mix-url> <mix-id> <rounds> <parallel>

# e.g.
$ zeus-client mix https://zeus-testing.grnet.gr/zeus/elections/election-uuid/mix/unique-id my-election 128 4

• election-mix-url the election mix URL as provided by the election administrator.

• mix-id is an election identification string used as a prefix for the generated filenames.

• rounds is an integer related to mixnet security parameters. Using a low number produces fast results but could diminish mix security. It is advised to use an integer equal or greater than 128.

• parallel should be set to the number of CPU cores of your system.

Decryption

1. Download election ciphertexts:

   $ zeus-client download ciphers "<trustee-login-url>" ballots-encrypted

2. Compute partial decryptions

   $ zeus-client decrypt ballots-encrypted ballots-partially-decrypted “<path-to-trustee-secret-key>”

3. Submit partial decryptions

   $ zeus-client upload factors ballots-partially-decrypted “<trustee-login-url>”