Both Rogers and Hayden said Snowden's leaks create serious national security problems for the U.S. There's evidence that the leaks have prompted terrorist organizations to shift their communication strategies to avoid surveillance, Rogers said.
The leaks will lead to a lack of trust in the U.S. government's ability to keep secrets, Hayden added. "Why would anyone, domestic or foreign, be willing to have confidence in the United States to undertake anything that requires any kind of discretion ... in order to go do things that are lawful, appropriate, effective, but edgy?" he said.
Hayden, responding to recent criticisms of the NSA's dual role of surveillance and cybersecurity, defended the agency. The NSA exploits vulnerabilities in communications but determines when there are vulnerabilities that "nobody but us" can take advantage of, he said.
Reported back doors on the Internet that the NSA exploits could be vulnerable to other attacks, one audience member said.
"What do you with a vulnerability?" Hayden said. "Do you patch it, or do you exploit it? If even with the vulnerability, it requires substantial computational power, substantial other attributes, you have to make the judgment, 'who else out there can do this?'
"If there's a vulnerability in here that weakens encryption, but you still need four acres of Cray computers in the basement in order to work it, you kind of think ... 'that's a vulnerability that we are not ethically or legally compelled to try to patch'," he added. "It's one that ethically and legally we could try to exploit in order to keep Americans safe."
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