Diego Aranha (and his peers) has been presenting strong cases and amazing proofs over the years why the software stack in those voting machines is bugged beyond repair (specially considering they never have permanent uncontrolled access to scrutinize it, because if they did they would uncover with evidences some very dirty stuff) and it's disgusting to see him being a target of ad hominem and FUD by many political leaders and electoral judges in Brazil. Just so you have more context on this.

EDIT: Brazil has over 2 decades of electronic voting "experience", so you see how important papers like this one are for democracy and electronic voting in other countries