How vulnerable are Pennsylvania's electronic voting machines?

Pennsylvania voting system
Pennsylvania voting system 02:19

Donald Trump is warning about the possibility of voter fraud -- and one city he’s pointed to is Philadelphia.

In a Philadelphia warehouse, almost 4,000 electronic voting machines are ready to be rolled out. But some cybersecurity experts warn the machines - which are used in most Pennsylvania counties - are vulnerable. 

“It’s a relatively lucrative target if you want to try and manipulate something,” said Ben Johsnon, a former NSA engineer now with cybersecurity group Carbon Black. “It’s really around creating doubt: doubt in democracy; doubt in the integrity of the election process.”

He said these direct recording electronic machines don’t have paper backups of each ballot cast, making a recount in a tight race difficult.

Pennsylvania ballots for the 2016 election. CBS News

Donald Trump has singled out Philadelphia as being a hotbed for voter fraud.

“We have to make sure the people of Philadelphia are protected and that the vote counts are 100 percent,” Trump said in Wilkes-Barre. 

Johnson said he has confidence in the voter machines in Philadelphia.

But Republican elections commissioner Al Schmidt sees some issues with Pennsylvania’s voting procedures. He wrote a report on voting irregularities during the 2012 election. There have been dozens of cases but only 10 prosecutions.

How real is voter fraud? 03:32

“Voter fraud does occur, but that’s a completely different animal from vote rigging, right, or rampant voter fraud, which would involve hundreds of people stealing thousands of votes to change the outcome of a presidential election,” Schmidt says. 

Schmidt says even without a paper trail, the electronic machines are safe because they do keep a digital record of votes cast. And, he points out, the individual machines are not connected to the internet.

“Our voting system has more in common with household appliance than a laptop or anything like that,” Schmidt said. 

That means the machines themselves are not vulnerable to a cyberattack: With other aspects of the voting system online, Pennsylvania is one of about 40 states to seek cybersecurity assistance from the Department of Homeland Security.