Electronic Voting Machine series: voting machine ecosystem is fully developed by the TSE

Electronic Voting Machine series: voting machine ecosystem is fully developed by the TSE

A picture that show how is inside of an electronic voting machine

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On October 5 next year, when over 141 million Brazilians will face one of the 534,000 voting machines made available for next year’s elections, they can be certain that their voting will be completely safe and reliable. Over the last 17 years, four presidential elections and five municipal elections have been held without any results ever being brought into question.

Voting with such assurances requires more than the simple manufacturing of the voting equipment itself. Much before the elections, the Superior Electoral Court (TSE) initiates the development of the so-called voting machine ecosystem, which is the set of software solutions that allow the TSE to support and automate the activities and processes involved in the operation of the electronic voting machine, from the treatment of the medias to the counting of the results of each polling station. It functions as a unit that interacts around the electronic voting machine.

Every election cycle, the software development teams from the TSE produce and develop all election software themselves, including the code to be embedded in the voting machines. The current ecosystem covers 27 different systems.

Some of those include:

-   The GEDAI-UE or Data, Applications and Interface Management System, which provides the electoral registry offices and Regional Electoral Courts (TREs) with the software support required for the loading of data into the electronic voting machines, managing, in particular, the voting machine medias (namely the load, voting and result storage medias);

-   the SCUE, or Voting Machine Load System, responsible for preparing and installing the operating system, software and election data in the voting machines;

-   the ATUE, or Voting Machine Self-Test System, whose role is to perform tests to validate the operation of the voting machines before election day; and

-   the VOTA, or Voting System, which collects and calculates the votes from a polling station - this is the software used by millions of Brazilians on election day.


According to Electoral Law, beginning six months before the first round of elections, political parties, the Brazilian Bar Association (OAB) and the General Attorney's Office are allowed to monitor the specification and development stages of the software used by the electoral systems. They can do so through qualified representatives formally appointed as such via the Secretariat of Information Technology (STI) of the TSE. Once completed, the software programs to be used in the election process are digitally signed by those entities and by authorities of the TSE, an act that takes place during the Digital Systems Signing and Seal-off Ceremony held by the Court.

Soon after digital signature, digital abstracts (hashes) are generated for each program developed which serve to confirm that the digitally signed program is the same as the one to be used in the elections. The hashes are delivered to the political parties, the OAB, and the General Attorney's Office, and are also published on the TSE Portal. These programs are written in non-rewritable media, sealed and stored in a safe at the STI.

About a month before the elections, the TREs receive the programs that will be used in the voting and counting of results. The Regional Courts then hold public hearings themselves, during which one can check the authenticity of the hash of the program that is installed by matching it with the one stored in the TSE. 

Data load

Also during the public hearings, the TRE (or the electoral registries themselves) use the GEDAI-UE to generate the load flash memory, which initiates the preparation of the voting machines and contains the data from voters and candidates, followed by the voting flash memory and the voting result flash memory.

Hundreds of thousands of electronic voting machines receive their flash loads one by one. Each voting machine whose data has been loaded has a unique identifier generated by SCUE, called "correspondence", or “matching” number. This number is generated from the serial number of the voting machine, the polling station where it will be used and its municipality, as well as other elements that make this number unique for each time the voting machine is loaded. This unique number is stored in the load flash so that it may later be submitted to the aggregation system by the GEDAI-UE. This way, the final result of the votes in a given voting machine, duly reported in its bulletin, can be validated as being that of a voting machine prepared by the Electoral Justice.

Afterwards, the load flash, the voting flash and then the result records flash are loaded. Shortly thereafter, the voting machine runs the ATUE system, which checks if the voting machine and its components are functioning properly. The entire procedure is accompanied by political parties, the OAB and the General Attorney's Office. At no time is the voting machine connected to any communications network.

The voting machine is then sealed and programmed so that the VOTA system will only work on election day, when millions of Brazilian voters will choose, securely and transparently, their next President, Governors, Senators and Federal, State and Federal District Representatives.