Brazil's Rapid Electronic Vote Tally Highlights U.S. Security Concerns
As the U.S. approaches its midterm elections, Brazil's efficient and audited digital voting system offers a contrasting model for election security.
Brazil's presidential election on October 4 demonstrated the speed and security of its electronic voting system, which tallied approximately 125 million votes in under four hours, leading to a runoff between Senator Flavio Bolsonaro and President Luiz Inácio Lula da Silva.
This efficiency has drawn attention from U.S. observers as the midterm elections loom. Brazil's system, in place for over three decades, is the world's largest digital voting system, is completely disconnected from the internet, and is robustly audited. It was also cited in a 2025 executive order by then-President Donald Trump, who noted Brazil’s biometric voter identification as an example, even as he vowed to scrap paperless machines.
A Secure and Audited Process
Brazil's electronic voting machines, used by nearly 90% of voters who often verify their identity with a fingerprint, have operated without proven fraud since their debut in 1996, according to the Superior Electoral Court (TSE). The 499,248 machines used in the October 4 election were not connected to the internet, and their software was made available for inspection by political parties, universities, and watchdogs for 11 months prior to being digitally signed and sealed. In December, the government invited 149 external evaluators to test the system's security, but they reportedly found no vulnerabilities that could alter election results or compromise voter privacy.
On election day, randomly selected machines are audited on camera with paper ballots, observed by federal auditors and foreign delegates. After polls close, each machine prints a tally report, which is posted at the polling station along with a QR code, allowing the public to cross-reference it with the national count. The TSE confirmed that each result file carries a digital signature verifying its origin from the specific machine.
Karina Stange Calandrin, a political scientist, described the system as combining electronic voting, local storage of hashed voter eligibility, and automated tallying, creating a secure process. "The machines never connect to the Internet and even the central database system used to transmit tallied votes to TSE must match results issued physically and locally by each individual machine without human interference," she stated, emphasizing the difficulty of undetected collusion required to corrupt the system.
The system's integrity faced scrutiny in 2022 when former President Jair Bolsonaro, who is currently serving a sentence for efforts to overturn his election defeat, attacked the credibility of the electronic voting machines without evidence. This year, his son, Senator Flávio Bolsonaro, is in a runoff position, potentially benefiting from the very system his father criticized.
Florencia Ferrer, CEO of e-stategiapublica, considers Brazil's system the most modern and secure globally, contrasting it with other countries' methods. Experts from the University of São Paulo’s Polytechnic School, who audited the machines in 2014, have also reported no evidence of tampering or malicious intent, though they acknowledge no system is entirely infallible.
However, some security researchers and organizations, such as the Carter Center, advocate for voters to receive a printed version of their ballot to deposit separately. Germany's highest court has also ruled that voters must be able to verify their ballot without expert assistance, which effectively bars systems similar to Brazil's. Brazil has loaned its voting machine technology to several countries in Latin America, Africa, and Asia, with Paraguay permanently adopting a version that prints individual votes since 2006.
In contrast to the decentralized nature of U.S. elections, run across thousands of jurisdictions with varied state rules and a significant reliance on mail-in ballots, Brazil operates with a single national election authority, compulsory voting, and no mail-in option. This centralized approach allows for rapid results, with the winner typically known and certified within hours.