In the wake of the Paris terror attacks, international intelligence officials are working to figure out how the elaborate plot was organized under the radar.
There's new concern that terrorists may be using social media apps and even gaming consoles to send encrypted messages to avoid government interception.
"It's what we would call industrial strength encryption," said Steve Beaty, Computer Science Professor at Metropolitan State University Denver. "The data exchanged cannot be apprehended, cannot be read."
Apps like Telegram, WhatsApp, and Signal are well-known for encrypting messages. Beaty says he uses Signal to communicate with colleagues.
He says terrorists don't need to be very savvy to use what's already at their fingertips. Another example of encrypted technology can be found in gaming consoles, like PlayStation 4.
Belgium's federal home affairs minister has mentioned PlayStation 4 messaging is more difficult to intercept than messages from WhatsApp.
"The Xboxes and the PlayStations have more graphics capabilities, and as it turns out, that does help in the encryption, because you can use those strong graphics cards to do encryption faster," said Beaty.
