Public audit mechanism used by the Electoral Court to verify the correct counting of votes and the security of electoral software
The legitimacy of the Brazilian democratic process is supported by a complex system of technological and procedural checks and balances. To understand what the integrity test of electronic voting machines is and how it works, it is necessary to consider it as one of the main stages of monitoring the electronic voting system. This procedure, carried out on the same day as the election, simulates a normal vote to prove that the vote typed by the voter in the ballot box is exactly the same as the one that will be counted by the computer.functioning as a real-time proof of concept of the reliability of the software and hardware used by the Electoral Court.
Nature and duties of the audit
The integrity test, technically, is a health audit. Its central task is to verify the consistency of the electronic voting machine’s behavior under normal conditions of use. Unlike a source code analysis — which takes place in previous steps and in a controlled environment — this test focuses on the practical result of the interaction between the voter and the machine.
The primary functions of this procedure include:
- Match Check: Ensure that the choice entered on the ballot box keyboard faithfully corresponds to the digital record recorded in the machine’s memory.
- External supervision: Allow supervisory entities (political parties, Brazilian Bar Association, Public Ministry and civil society) to monitor the flow of voting and counting.
- Fault detection: Identify possible anomalies in the functioning of the equipment or the ballot box’s operating system in an intensive use scenario.
Historical context and normative evolution
The implementation of this audit is not new. The procedure was established by the Electoral Court in 2002, under the name “Parallel Voting”. The name change to “Integrity Test” occurred later, aiming to make the term more descriptive and transparent for the electorate.
Historically, the process is regulated by resolutions issued by the Superior Electoral Court (TSE) each electoral cycle. TSE Resolution No. 23,673/2021, for example, consolidated the guidelines for the inspection and audit procedures of the electronic voting system. Since its creation, the test has evolved to include a greater number of ballot boxes audited and, more recently, the introduction of pilot projects with biometrics, expanding the layers of security verification.
Operating procedures and operation
To understand how the integrity test of electronic voting machines works in practice, one must observe the rigorous sequence of acts that begin on the eve of the election and continue until the end of the official vote. The process takes place in the Regional Electoral Courts (TREs) and in designated public places, being fully filmed and open to the public.
Operation follows the following critical steps:
- Draw or choice of ballot boxes: On the eve of the election, in a public ceremony, the ballot boxes that will be subjected to the test are drawn or chosen by the supervisory entities. These ballot boxes, which were already configured and sealed for use at actual polling stations, are removed and replaced with contingency ballot boxes.
- Transport and security: The drawn ballot boxes are transported under police escort to the integrity test location, usually the TRE headquarters or another public building.
- Preparation of paper ballots: Paper ballots filled out in advance by representatives of parties and coalitions are deposited in sealed canvas ballot boxes. These paper votes serve as the “ground truth” for the subsequent conference.
- Voting simulation: On election day, at the same time as the official vote (from 8 am to 5 pm), Electoral Court employees and representatives of supervisory entities remove the paper ballots from the canvas ballot box, type the votes in the electronic ballot box and record the process on video.
- Conference of results: At the end of the day, the electronic voting machine issues the Ballot Box (BU), which contains the sum of the votes entered. This electronic result is compared with the manual counting of votes from paper ballots. The objective is for there to be a 100% coincidence between the two results.
In recent elections, the “Integrity Test with Biometrics” was also introduced in real polling stations, where volunteer voters, after officially voting, unlock a test ballot box with their biometrics for auditors to carry out the verification, ensuring that the biometric system is also tested in a real scenario.
Institutional importance and impact on transparency
The relevance of the integrity test lies in its ability to materialize the security of electronic voting in an understandable way. By creating a physical mirror (paper ballots) of an electronic vote and demonstrating that the totals coincide, the Electoral Court offers a technical answer to questions about the inviolability of the ballot box.
Furthermore, the procedure reinforces the sovereignty of the electoral process by decentralizing supervision. The presence of external auditors, including experts from the Federal Police and representatives of international organizations, ensures that the system does not operate in a “black box”, but rather under constant public scrutiny. The redundancy generated by the comparison between the physical and digital media is a fundamental pillar for the acceptance of poll results.
The integrity test is therefore consolidated as an indispensable tool in the legal and technological framework of the Brazilian electoral system. By validating the exact correlation between the voter’s intention and the digital record, the procedure mitigates risks of misinformation and strengthens trust in democratic institutions, demonstrating, in each election, the robustness and auditability of electronic voting machines.
