Wiretapping is one of the oldest forms of hacking. With the emergence of cellphones, it took a wireless form and has been used extensively by the FBI, NSA and by criminals alike. This puts all our calls and messages at great risk of getting exposed as it is being sent as plain voice data and text.
A Pittsburgh-based startup, Whisper Systems has come up with an excellent solution. Now, you can place safe and secure calls on your Android device with their apps.
The first in this list is the RedPhone app. With this app, you can place secure phone calls over a VOIP network. RedPhone uses a voice cryptography scheme which lets us verify the two communication ends by sharing a passphrase. This is a classic example of shared key which is weak in itself but provides an added bit of security when used with the voice encryption.
The second once is TextSecure, which lets you send encrypted and scrambled text messages. Every text message being sent triggers the encryption system which in turn generates a new key, deletes the old one and encrypts the message being sent, by that key.
These apps have been released as public betas and are still under development. Moxie Marlinspike, a famous security analyst and the founder of Whisper Systems has plans for a seamless integration of his products as Android defaults.
Marlinspike has also assured the availability of both a free and a paid version of this app.
With the adoption of this app, there will be sparks of criticism against wiretapping which can lead to security concerns. Though, one good thing that can emerge from this is the improvement of privacy voice privacy over GSM networks.
In the meanwhile, you can try out the apps at Whispersys.