Director of National Intelligence James Clapper said Monday that the Snowden revelations have sped up the sophistication of encryption by "about seven years," according to the Christian Science Monitor

"From our standpoint, it’s not a good thing," Clapper reportedly said at CSM's breakfast event. When asked how he came up with that figure, he cited the National Security Agency.

“The projected growth, maturation, and installation of commercially available encryption—what they had forecasted for seven years ahead, three years ago—was accelerated to now because of the revelation of the leaks," Clapper continued.

Clapper noted that the Islamic State is "the most sophisticated user by far of the Internet," adding that the group buys software "to ensure end-to-end encryption" of its communications. The Monitor did not seem to ask Clapper which software he was referring to.

Other media outlets have reported that ISIS is known to use Telegram and WhatsApp for end-to-end encrypted messaging. Recent stories from The New York Times suggest that ISIS is also using TrueCrypt , a well-known file-encryption software. All of these tools are free to use.

Clapper went on to reiterate President Barack Obama’s warning against "absolutist positions" when it comes to encryption.

"I don’t know the technicalities of how we might arrive here, how we thread the needle" between how to "ensure privacy and security on an individual basis, as well as security in the context of what’s best for the collective good," Clapper said.

Cryptography experts and technologists have repeatedly said that allowing secure communications for all while giving law enforcement and government officials a method to access some materials would lead to compromised security.