Central Senate Scrutiny – security and integrity

Updated: 7 July 2022

Ensuring the security and integrity of ballot papers is integral to the AEC maintaining an impartial and independent electoral system.

All activities involving ballot papers – printing, transport, issue, voting, sorting, counting, movement and storage – are designed to safeguard the security and integrity of the ballot paper. The AEC’s operations and procedures, including the Ballot Paper Principles and Ballot Paper Handling Policy, mean that at all times, all ballot papers are tracked, secure and accounted for.

The Ballot Paper Principles:

  1. All ballot papers remain ‘live’ from printing through to statutorily authorised destruction.
  2. The security, integrity and accountability of ballot papers must be preserved at all times – including transit and storage by the AEC, contractors, or other third parties.

Ballot paper transport and tracking

After 6pm on election day, all polling places complete a first preference count of Senate ballot papers. The ballot papers are then packed into ballot paper transport containers (BPTC), sealed and taken to the divisional out-posted centre. Here a further first preference count is undertaken and then the ballot papers are despatched to Central Senate Scrutiny (CSS), again in BPTCs.

Every BPTC is clearly labelled and sealed with two unique seals used to detect if it has been tampered with. Each time a BPTC is opened or sealed (including at the CSS), an entry is recorded/logged.

Ballot paper transport containers are tracked via tracking forms for each and every transfer of custody. Tracking forms are completed at the time the transfer of custody takes place. At the CSS, ballot paper transport containers are tracked electronically.

Transport of ballot papers is by AEC staff or an approved courier authorised to undertake transport, with appropriate security controls.

Ballot paper secure storage and work zones

Ballot paper secure zones are designated areas at the CSS for handling or storing ballot papers.

Any time ballot papers are not in a ballot paper secure zone they must be under the supervision of an authorised person.

Scrutineers are not permitted in ballot paper secure work zones, however, scrutineers can observe all work done in these areas.

Scanning and verification

At the CSS, the AEC conducts the Senate count using a semi-automated process, scanning Senate ballot papers and using optical character recognition technology to capture preferences, which are then verified by a human operator.

Batches of Senate ballot papers are scanned and entered into the imaging software. The system generates metadata for each scanned ballot paper and a digital signature is applied to the data that allows the AEC to detect if the files have been tampered with between generation and loading into the count system.

Once each Senate ballot paper is digitised and the marks interpreted by the imaging software, any ballot paper with unknown preferences or unusual markings is referred to a human operator for verification of the marks on the ballot paper.

All ballot papers are then passed to a second human operator for full blind entry of all preferences on the ballot paper and comparison with the scanned and, if applicable, verified data against the full blind data entry. Once verified, a record is generated that represents the preferences on the ballot paper.

During the process at the Central Senate Scrutiny the AEC engaged an independent auditor to conduct an assurance process where the data captured in the AEC’s systems was compared to the data recorded on the Senate ballot papers to show the accuracy of the processes. For more detail please see the:

Review and adjudication

If a discrepancy occurs during the verification process, the image and data preference record is directed to the AEC for adjudication and resolution.

Scrutineers may view the scanning, verification and adjudication processes. If they wish, they may raise challenges for adjudication by the Australian Electoral Officer (AEO).

Storage and destruction of ballot papers

At the CSS, ballot papers are stored in Ballot Paper Secure Storage Zones. Long term storage of ballot papers is at third party secure records management facilities contracted by the AEC.

Ballot papers are destroyed at the authorisation of the Electoral Commissioner only in accordance with the relevant provisions of the Commonwealth Electoral Act 1918.


The AEC works closely with external partners to deliver a range of physical and cyber security measures.

AEC systems are segregated in a secured network, continuously monitored for unauthorised access. Attempts to access the network are audited and the AEC security team is alerted to any unusual or unauthorised attempts to access the network.

Independent assessors, accredited by the Australian Signals Directorate, have conducted security risk assessments of the computer systems used to scrutinise the votes in a Senate election for Australian States and Territories. This includes the systems used for scanning ballot papers and counting votes. The assessors provided written reports of the assessments to the Australian Electoral Commission (AEC), which included recommendations to reduce any risks that could affect the security of the computer systems. These recommendations have been accepted by the AEC and appropriate mitigations have been implemented to manage these risks.

In accordance with best practice, a cryptographic digital signature protects each preference data record from modification. The AEC retrieves the preference record, imports it into the AEC’s Senate count system and determines the result.

Physical security at all CSS sites includes 24 hour security guards and patrols, CCTV monitoring, and smart card access.

All staff and visitors must provide a valid ID and sign in before they are permitted to enter the CSS building; and visitors, including scrutineers, will be escorted at all times and required to keep to designated scrutiny areas. The AEC Election Personnel Identification Policy applies at CSS sites and outlines mandatory protocols on visual identification of AEC staff, visitors and scrutineers.