Brazilian electronic machine systems are fully developed by the TSE

Imagem mostrando a urna eletrônica.

On October 5, when more than 141 million Brazilians are expected to make use one of the 530 thousand electronic voting machines to cast their votes, they will do so reassured that their votes will be cast in a totally safe and reliable environment. Over the past 18 years, electronic voting machines were used in four presidential and five municipal elections, generating results that did not raise any serious questioning.  

Nevertheless, the manufacturing of voting machines is not sufficient to ensure safe voting. Long before elections are held, the Superior Electoral Court (TSE) begins to develop an ecosystem for voting machines. Such ecosystem consists of a set of software solutions that provides for the support and automation of activities and procedures related to electronic voting machines, ranging from the handling of different media to the counting of votes in each polling station, serving as a unit that interacts with electronic voting machines.

Every time an election is held, TSE software development teams produce and develop all election solutions, including the programs that will be installed in electronic voting machines. The current ecosystem encompasses 27 systems.

These systems include: GEDAI-UE, a manager of data, programs and interface with electronic voting machines, which provides the team of electoral registers and Regional Electoral Courts (TREs) with software support necessary for the loading of electronic voting machines, especially the running of voting machine media (loading and voting flashes, and result memories); SCUE, a loading software that prepares and installs the operational system, election software and data in the electronic voting machines; ATUE, an auto-testing program that runs tests one day before Election Day in order to validate the operation of electronic voting machines; and VOTA, a software that collects and counts the votes cast in each polling station, and is used by millions of Brazilians on voting day.


As of April 7, political parties, the Brazilian Bar Association (OAB) and the Prosecution Office may formally appoint to the Information Technology Secretariat (STI) qualified representatives to oversee the stages of specification and development of electoral systems. These appointed experts are authorized to run and review electoral computer programs during work days (Monday to Friday), from 8 a.m. to 6 p.m. at the Presentation Room (Room A-361), located at TSE´s main office building in Brasília.

The above-mentioned procedure is established in Law n. 9,504/1997 (Article 66, Paragraph 1) and in TSE Resolution n. 23,397/2013, which provides for the ceremony of digital signature and inspection of the electronic voting system, digital recording of the votes, parallel voting and procedures to ensure the safety and integrity of electoral system data. All electoral systems and programs are developed by the Information Technology Secretariat of the TSE.

Such monitoring and oversight may be carried out until the day before the Ceremony of Digital Signature and Sealing of Electoral Systems, which occurs 20 days before elections are held. This year, this ceremony is scheduled to take place on September 15-17, and will encompass an opportunity for accredited representatives nominated by political parties and coalitions to learn about all programs developed to be used in the elections, and to review such applications, especially source-programs and executable programs.

After ceremony attendants learn about such programs and review them, these applications will be compiled and digitally signed by the concerned representatives of the political parties and coalitions, of the OAB and the Prosecution Office, in addition to being further tested and digitally signed by the TSE. After being digitally signed, each developed program will have a digital digest (hash) generated for it so as to confirm that the digitally signed application is the same one to be used during elections. These hashes will be forwarded to the political parties, the OAB, and the Prosecution Office in addition to being also published on the web portal of the TSE.

Next, after the compilation of all electoral systems, their final version will be recorded in non-rewritable media, and will then be physically sealed and sent to the safe-room of the Court, where they will remain stored. The Electoral Court System is responsible for ensuring that private electronic keys, and electronic access passwords remain confidential and undisclosed.

The fact that such programs can only run in the computers of Electoral Courts, being activated by passwords generated by the TSE, consists of another relevant safety measure. Thus, even in the event that the systems get to be intercepted, it is not possible to install and run their files in external computers.

Finally, the digitally signed and sealed electoral systems will be distributed through the private network of the Electoral Courts to the Regional Electoral Courts (TREs). These courts may then organize public hearings to check whether the hash of the program installed in TRE computers is authentic and whether it matches the one forwarded by the TSE.

After elections are held, political parties may also check, upon prior scheduling, all source-programs that were used during the event. The access to these programs will also take place at Room A-361, located at TSE´s main office building, and may be carried out until the next election process is held.


Regional Electoral Courts or even electoral registers may also organize public hearings to execute GEDAI-UE in order to generate a loading flash, which initiates the preparation procedures of electronic voting machines, carrying data on voters and candidates, voting flash, and result memory.

The hundreds of thousands of electronic voting machines that will be used in Brazil´s elections receive each a loading flash. A unique number, also known as corresponding number, is generated by SCUE at each loaded voting machine. Such number is generated after many different features, including the serial number of each voting machine, the polling station and the municipality where it will be placed, which result in a unique number every time the voting machine is loaded. This unique number is recorded in the loading flash to be later forwarded by GEDAI-UE to the counting system. Thus, the final count of votes cast in a voting machine, which goes featured in the voting machine report, is validated and recognized as a result delivered by a voting machine that had been previously prepared by the Electoral Court System.

After loading flash is activated, the voting flash and the result memory are inserted. Next, the electronic voting machine will run the ATUE, a program that checks whether the voting machine and its components are working properly. This procedure may also be monitored by political parties, the OAB, and the Prosecution Office. The voting machine is not connected to any sort of communication network during this stage.

The voting machine is then sealed and configured to run the VOTA, which purpose is to collect and count the votes cast in each polling station, only on Election Day, when millions of Brazilian voters will elect, in a safe and transparent manner, Brazil´s president; state governors; senators; federal,  state and district representatives.