An election in ElectionGuard is defined as a set of metadata and cryptographic artifacts necessary to encrypt, conduct, tally, decrypt, and verify an election. The Data format used for election metadata is based on the NIST Election Common Standard Data Specification but includes some modifications to support the end-to-end cryptography of ElectionGuard.
Election metadata is described in a specific format parseable into an Election Manifest and its validity is checked to ensure that it is of an appropriate structure to conduct an End-to-End Verified ElectionGuard Election. ElectionGuard only verifies the components of the election metadata that are necessary to encrypt and decrypt the election. Some components of the election metadata are not checked for structural validity, but are used when generating a hash representation of the Election Manifest. Additionally, a context is created during the Key Ceremony that includes the cryptographic artifacts necessary for encrypting ballots.
A core component of the ElectionGuard security architecture involves election guardians. Election guardians are trustworthy, independent individuals that participate in the key and tally ceremonies of ElectionGuard e2e-v elections.
By using multiple guardians to conduct the tally process, no one person controls all the keys necessary to decrypt ballots. However, with multiple actors it becomes necessary to compensate for guardians going missing or obstructing the tally process by supporting quorums and dispute resolution when a guardian challenges a result, as they are allowed.
As such, it is necessary when setting up an election to specify the maximum number of guardians that can participate, but also the quorum, the minimum number of guardians necessary to perform a tally. The more guardians that are allowed, the higher the quorum can (and should) be set (a high number of guardians with a low quorum creates an opportunity for collusion among guardians). It is advised to set quorums not just above majority levels but as high as can be reasonably expected (e.g. set a quorum of 5 or 6, not 4, for an election with 7 guardians).