You can now make encrypted phone calls on your iPhone thanks to this app that can keep out snoops and even the NSA. The best part is the new app is its absolutely free!
Signal was developed by Open Whisper Systems and uses secure ZRTP and AES 128 encryption to keep your phone calls private. Both callers must have the app for it to work, but it shouldn't be too hard to convince your friends and family to download it since it doesn't cost a dime. Text messaging services are also coming to the app soon.
ZRTP is an encryption technology developed by Philip Zimmermann and used in his own iPhone encryption service called Silent Circle. This is mostly used by businesses because it costs $20 a month. Once you make a call, a two word password shows up on the screen for both callers. This is another way to confirm that you're speaking to the right person.
Wired tested an early version of the app that had a few glitches, but the developer has said that they have been taken care of. Most new apps have a few hiccups before they're perfected.
Like any new and relatively untested crypto app, users shouldn’t entirely trust Signal’s security until other researchers have had a chance to examine it. Marlinspike admits “there are always unknowns,” such as vulnerabilities in the software of the iPhone that could allow snooping. But in terms of preventing an eavesdropper on the phone’s network from intercepting calls, Signal’s security protections are “probably pretty great,” he says.
Android users can find a similar app called Redphone that was also developed by Open Whisper Systems.
The government isn't going to stop spying anytime soon, so this app is a great - and free - way to secure your phone calls.