It is very easy but more costly than a recount to verify the integrity of an election. Auditing relies on the assumption that real voters can be linked to atte

It is very easy but more costly than a recount to verify the integrity of an election. Auditing relies on the assumption that real voters can be linked to attestations and the aggregate of attestations can be linked to the aggregate of votes. In Australia when you vote in person your named is checked off on the electoral roll. This is an attestations. When you submit an absentee ballot you also fill out a form. This is an attestation as well. The audit does a full recount of attestations and votes and verifies the totals are the same. Duplicate checking is also performed on attestations. Furthermore, the attestations are randomly sampled and the real voters are interviewed to check if they actually voted. In the case of absentee ballots the details on the form can be checked as well. The random sample is performed so you have an ‘acceptable’ level of fraud and then you sample enough ballots such that if you were higher than the acceptable level it would be likely to sample a fraudulent ballot. This process breaks down a bit at this point because of the issue of false positives where the voter cannot be contacted. However, with more work from the auditor it is often possible to distinguish between the voter being uncontactable and voting and the voter not existing, or being uncontactable and not voting. Because the audit process establishes a trail from real voters to real ballots it is very difficult to commit electoral fraud. There are some forms of electoral fraud this audit will not detect like bribery and coercion. It also doesn’t prevent substitution attacks where someone destroys real ballots and replaces them with dodgy ones.