The three candidates for Georgia secretary of state on Tuesday debated how to replace the state's outdated voting machines and protect the sanctity of elections from outside interference.

Democrat John Barrow committed to using the power of the secretary of state to quickly move to unhackable paper ballots. Republican Brad Raffensperger said his business experience as an engineering firm's CEO makes him the most qualified to run a complex government office. And Libertarian Smythe DuVal said he's the only independent fiscal conservative in the race.

The winner of the Nov. 6 election will be responsible for overseeing Georgia’s elections, business registrations and professional licensing. Georgia’s current secretary of state, Republican Brian Kemp, is running for governor against Democrat Stacey Abrams and will leave office at the end of the year.

Raffensperger, a state representative from Johns Creek, said he would cancel the registrations of ineligible voters to ensure election integrity. The Georgia Secretary of State's Office last year canceled 668,000 registrations of voters who hadn't participated in elections in several years, or who had died, moved or been convicted of a felony, among other reasons.

"By keeping the voter rolls updated, we can help safeguard and keep our elections clean so we know that the person who won actually did win," Raffensperger said during the debate presented by the Atlanta Press Club and aired by Georgia Public Broadcasting. "I'm the only business owner in this race that has run an office the size of the Secretary of State's Office."

Barrow, who served in Congress for a decade, said he's more concerned about the threat of hacking or foreign interference after Russians attempted to sway the outcome of the 2016 presidential election.

If elected, Barrow said he would decertify Georgia's direct-recording electronic voting machines, which don't leave a verifiable paper trail showing voters' intent. State legislators plan to consider buying a new statewide voting system next year, but Barrow said Georgia's touchscreens are too unsafe to continue using in the meantime.

“They’re not good enough for elections because they can be hacked,” Barrow said. “What we need is to decertify these machines and move to the process currently allowed by state law, which is hand-marked paper ballots using optical scanners.”

DuVal, an information technology graduate student and registered nurse, said hand-marked paper ballots are the most secure and cost-effective voting system. He said taxpayers shouldn’t have to pay more than $100 million for the type of voting system preferred by Raffensperger, called ballot-marking devices, that would use touchscreen voting machines to print out paper ballots.

“I want to fix Georgia’s broken election system,” DuVal said. “I’m sick and tired of the partisanship between the Democrat and Republican party. We are pursuing competitive, fair and secure elections.”

DuVal also said Georgia should adopt same-day voter registration as a way to make it easier to vote and ensure accurate voter registration lists.

Barrow attacked Raffensperger, calling him a "rich deadbeat" for failing to pay off more than $5,000 in old tax liens until it became an issue in the Republican primary election against former Alpharetta Mayor David Belle Isle.

“If that ain’t disqualifying, it should be,” Barrow said.

Raffensperger responded that his businesses pay more than $1 million in taxes nationwide annually, and he resolved the tax dispute when it came to his attention this summer.

“One of the things I do every day, as an engineer and a business owner, is solve problems,” Raffensperger said. “That’s what I want to do” as secretary of state.

The debate will be broadcast on Georgia Public Broadcasting at 7 p.m. Wednesday.