Elections in the ACT are at risk of foreign interference and corruption because they heavily rely on an electronic system which cannot verify votes have been accurately recorded, three experts say.
The use of voting systems that do not have a "human readable paper trail" should be banned, the trio has told a parliamentary inquiry.
Associate Professor Vanessa Teague, a researcher at the Australian National University, Dr Andrew Conway and T Wilson-Brown told the inquiry into proposed changes to the territory's electoral laws Assembly elections were particularly vulnerable because of the "huge numbers of unverifiable votes".
"No other Australian jurisdictions, and very few other democracies in the world (excluding Brazil), take the overwhelming majority of votes through a system that voters and observers cannot check," the trio wrote.
"Running elections over the internet increases the ease of attack, but doesn't fundamentally alter the threat - if anything, the pollsite system is more dangerous because it takes the huge majority of votes."
Dr Teague told The Canberra Times voters should elect to cast their ballots on paper.
Voting systems with a paper trail could either require voters to fill out paper ballots which are then scanned to be counted, or an e-voting system that prints out a record of the cast ballot and can be used to audit the electronic counting, Dr Teague said.
The submission said assurances from Elections ACT that the outcome of the election is trustworthy because the Australian Signals Directorate had endorsed the source code of the system missed the point.
"The system is inherently brittle because, in the event of a compromise, misrecording of votes could be undetectable. Malware on remote personal devices that individuals use to vote online could misrecord their votes before they are sent to the server," the submission said.
"Similarly, even if the EVACS software is perfectly secure and absolutely correct, physical or electronic voting problems at the polling place (or before the computers arrive at the polling place) could allow it to be substituted.
"In the last election, there were errors in Elections ACT's vote counting code - it is not credible that they can guarantee the security and correctness of all code and devices used in either pollsite or internet voting."
The three researchers said there was no known way of adequately ensuring internet voting was secure while also preserving the privacy of voters.
The ACT electoral commissioner, Damian Cantwell, told budget estimates last week Elections ACT expected to use its electronic voting system at the 2024 election, but the number of e-voting booths was yet to be determined.
"The experience in 2020 highlighted the increasing community expectations and indeed satisfaction with that form of delivery of voting. It provides a very convenient, quick and trusted means of members of community casting their votes," Mr Cantwell said.
About 70 per cent of votes in the last territory election were cast with electronic voting, he said.
Mr Cantwell said the voting software would be available for public scrutiny at least six months before the October 2024 election and he did not intend to require people to sign non-disclosure agreements before accessing the code, unlike before the 2020 poll.
The expert submission had recommended the non-disclosure agreement requirement be dropped for people seeking access to the code.