iPhone gets voice scrambling app to thwart government surveillance

Signal, a free app for iOS on iPhones, is an open-source app which can scramble voice calls and deter spying agencies and eavesdropping hackers who can tap into conversations.

Signal provides end-to-end encryption for your calls, securing your conversations so that nobody can listen in. Signal uses your normal phone number to make and receive calls, so you don't need yet another identifier.

However, Signal uses Wi-Fi or data, not your plan's voice minutes. In-short, the app uses the internet for voice calls instead of your GSM / CDMA service, which can be easily tapped by the government or the hacker.

Signal is completely free for iOS, requires a one-time SMS confirmation and will list those users who have the same application installed. Pretty much like WhatsApp with voice, right?

Well, this one goes a step ahead with authenticating a call. When you make a call over the internet, Signal displays two words on the screen, which need to be verified by the party on the other side. This ensures that there is no middle man in between.