Did Hillary Clinton's private email servers jeopardize Obama?

CHARLOTTE, NC - JULY 05: Democratic presidential candidate former Secretary of State Hillary Clinton (R) and U.S. president Barack Obama greet supporters during a campaign rally on July 5, 2016 in Charlotte, North Carolina. Hillary Clinton is campaigning with president Obama in North Carolina. (Photo by Justin Sullivan/Getty Images)

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Last Updated Oct 25, 2016 6:05 PM EDT

While Hillary Clinton served as secretary of state, she and President Obama exchanged emails, though exactly how many is unknown. White House Press Secretary Josh Earnest was asked about their correspondence in March 2015.

“The President, as I think many people expected, did over the course of his first several years in office trade emails with his Secretary of State.  I would not describe the number of emails as large, but they did have the occasion to email one another,” Earnest said at a press briefing.

In January, the State Department disclosed that it had withheld eight email chains that totaled 18 messages between the president and Clinton, which will remain confidential under the Presidential Communications Privilege. Given the existence of these exchanges between the president and Clinton, though, CBS News spoke to some cybersecurity experts about whether this might ever have inadvertently exposed the president to cyberattacks.

The FBI recently released records last month that detailed an interview with Clinton adviser Huma Abedin, in which she was shown an email exchange between Clinton and Mr. Obama. At first, she didn’t recognize that it was the president because he was using a pseudonym.

“Once informed that the sender’s name is believed to be a pseudonym used by the president, Abedin exclaimed: ‘How is this not classified?’” the report said. “Abedin then expressed her amazement at the president’s use of a pseudonym and asked if she could have a copy of the email.”

Herbert Lin, a senior research scholar for cyber policy and security at Stanford University’s Center for International Security and Cooperation, told CBS News one can’t conclude that any communications between the president and Clinton were compromised -- because even now, no one knows whether her server was ever hacked.

“We have a choice of thinking would the security risk have been worse with her private server -- which may or may not have been compromised -- vs. the State Department server which we know was compromised,” Lin said. “If I had to choose between those two, I’d say they were safer on her server than not...at least that’s what the evidence that’s been revealed to date suggests.”

As Lin mentioned, hackers breached the State Department’s unclassified email system in 2014. That’s not the case with Clinton’s server. FBI Director James Comey said in July that the agency had found no direct evidence that Clinton’s personal email domain had been successfully hacked. He didn’t rule out the idea that her account had been jeopardized, though. Because Clinton sent and received work emails while she traveled in territories where sophisticated adversaries operate, Comey said, “It is possible that hostile actors gained access to Secretary Clinton’s personal email account.” 

Whether the president knew Clinton was using a private server has also been questioned. In March 2015, he told CBS News’ Bill Plante that he learned about the private email server “the same time everybody else learned it -- through news reports.”

Earnest added that while the president knew Clinton’s email address, he “was not aware of the details of how that email address and that server had been set up.”

In any case, one cyber expert, James Lewis, who runs the strategic technologies program at the Center for Strategic and International Studies (CSIS), did a study that suggests we shouldn’t be surprised that Clinton didn’t use her official email address in her occasional notes with the president. Lewis’ research found most high-ranking officials use private email “because it’s just quicker than the official thing.” (In the president’s case, however, the type of email address he used is not known -- only that he used at least one pseudonym.)

And Lewis suggested that if their emails -- held on her private servers -- were hacked, we would probably already know.

“Usually the intelligence community gets really grumpy when one of their sources or operations has been compromised...and then they leak it,” Lewis told CBS. “Had there been a compromise, I think it probably would have been leaked and we haven’t seen the leaks. That’s how it’s always worked in the past.”

  • Rebecca Shabad

    Rebecca Shabad is a video reporter for CBS News Digital.