Whatsapp is a cross platform, instant messaging application for sending images, videos, audio messages and files from one user to another. Cross platform means it has different versions available for Android, iPhone, Symbian, Windows and Blackberry operating systems. This application is not device (phone), carrier or operating system dependent. Thus, it has user base of around one billion which makes it one of the most popular messaging application in a world!

Earlier (before the acquisition by Facebook) Whatsapp messages which were exchanged between users were stored in “msgstore.db” which is a SQLite databases. These messages stored in a database were not in an encrypted form. The whole conversation could be leaked from the database due to its poor security techniques. Anybody with good technical skills could easily decrypt the messages sent through Whatsapp because of its poor security techniques. For example they used same encryption key for both sides of conversation. Anyone who can eavesdrop on the Whatsapp connection could easily decrypt the messages exchanged.

To avoid these security attacks, Facebook the new owner of Whatsapp decided to choose other security techniques for end to end encryption. This results in a new partnership with Open Whisper Systems which provides the end to end encryption to the conversations.

Open Whisper uses Text Secure service which uses a cryptographic key that is unique for every device to provide security to its giant user base. The Text Secure uses “forward secrecy” protocol for providing keys. The end to end encryption works by storing the keys on a user’s device. When it is combined with the Text Secure it provides a fresh key for every new message.

So, the encryption technique which has been used by WhatsApp is now different from other instant messaging apps in terms of security because they store the keys on their own servers. However despite all the new encryption techniques the security cannot be granted 100% in this modern digital age.

By:- Ms. Vaishali Gupta – Asst. Prof. CSE, Chitkara University H.P.