Secure messaging became very popular over the last years. People started to switch to WhatsApp alternatives like Signal, Threema and Telegram. At SecuritayV we talked the security of some of those alternatives in our talk “Post Snowden Communication”. This year our talk focuses on the usability of Signal mobile and the security of the desktop variants “WhatsApp-Web” and “Signal Desktop”. The first part of this talk will cover a usability study on the Signal mobile application. During this study we determined how easy/difficult it is to verify a chat partner, send encrypted messages as well as the usability of the application overall. The results were worse than expected … The second part will be the security of WhatsApp-Web and Signal-Desktop. We will explain the process of linking new devices as well as certain attack vectors on both – Signal-Desktop and WhatsApp-Web. Possibilities and attack vectors for the browser to compromise the communication were also part of this research. Finally, problems with storing data on the local device will be discussed as well as information leakage issues with the exchange of certain information like groups or contacts will be explained.