Editor's note: This is one in a series of stories and opinion pieces surrounding the Aspen Security Forum currently taking place in Aspen, Colorado. Security Clearance is a media sponsor of the event, which is taking place from July 17 to 20 in Aspen, Colorado.
A senior-level defense official said Thursday that keeping top-secret information on one shared server and giving an individual the ability to view and move that data were two mistakes that allowed NSA leaker Edward Snowden to disclose top-secret information.
Although Ashton Carter, the deputy secretary of defense, said he didn't want to directly comment on Snowden - "because that is a criminal investigation" - he spent a portion of a panel at the Aspen Security Forum laying out the "root causes of all of this."
"This is a failure to defend our own network," Carter said. "That failure originated from two practices that we need to reverse."
The first mistake: "In an effort for those in the intelligence community to be able to share information with one another, there was an enormous amount of information concentrated in one place. ... It creates too much information in one place."
The second: "You had an individual who was given very substantial authority to access that information and move that information. That ought not to be the case, either."
Carter also said that the damage Snowden caused to the United States is "very substantial" and is still being assessed.
"We are acting to reverse both of those things," Carter said. "It is quite clear that those are the two root causes of this."
To correct these mistakes, Carter said, the intelligence community needs to "compartmentalize more rigidly" and not give so much access to one person, on their own.
Asked about the time frame for countermeasures being put in place to stop more leaks, Carter bluntly said, "Now."
Snowden, a former National Security Agency contractor, leaked classified NSA documents to the media, sparking worldwide controversy over U.S. surveillance programs.
Since leaking the information, Snowden has been a man without a country. He has received asylum offers from Venezuela, Bolivia and Nicaragua, but remains stuck in Moscow's international airport because the United States has revoked his travel documents.
Earlier in the session at Aspen, moderated by the New York Times' David Sanger, Carter spoke about the Pentagon's focus on cybersecurity and cyberwarfare. He laid out three priorities - defending the Pentagon's networks, attacking enemy networks and defending the nation's networks - as areas that the Defense Department is concentrating on.
In that effort, Carter said, 40 new cyberteams are working at the Pentagon. In total, he said, that is 4,000 people.
As for the cost of this new effort, Carter said it is "not very expensive." It is a priority for the department and will be protected from "budget hassles" that are currently looming over the Pentagon, he added.
– CNN's Elise Labott and Tom Cohen contributed to this report.