WhatsApp now uses full end-to-end encryption for messages sent between Android users, making it one of the most secure messaging platforms. To beef up its security, WhatsApp teamed up with Open Whisper Systems to use its open source encryption program, TextSecure.
With end-to-end encryption, WhatsApp can't read your messages nor decrypt them if the NSA comes knocking. Therefore, only the users at each end will be able to read the actual message and for others its just garbled text.
WhatsApp started working with Open Whisper Systems 6 months back to bring the feature to Android users. At present there is no word as to when it will be available on other platforms.
Source: The Verge
