Encrypted Chat Client : Encrypted communication over XMPP

Abstract: Every day there are internet users all over the world who sends a total sum of millions of emails and instant messages and a majority of these are sent and transmitted without any form of encryption. When we send an unencrypted message it can be monitored, analyzed and even stored by organiza-tions and individuals. Therefore using encrypted communication is vital for not having our privacy violated. One of the problems that needs to be solved is to allow two persons to communicate in (near) real time through text over internet in a secure and easy way for the user, while at the same time allowing the user to have a good experience and maintaining confidentiality. The chat client should be able to communicate with other platforms than only itself and must therefore use and fol-low an existing protocol for instant messaging. To receive a true end-to-end encryption, all data needs to be encrypted and decrypted locally on the user's computer before it is sent out on the inter-net. SSL / TLS can be used as a protective layer, but it must be complemented by an extra and sepa-rate layer of encryption since SSL / TLS is not an authentic end-to-end encryption. This is because of the SSL data is decrypted when they land on the server, while true end-to-end data is only de-crypted locally on the receivers computer. This thesis have resulted in a working chat client built on the XMPP protocol with support for using OTR encryption that offers true end-to-end encryption.