Exercise: Several software configurations can be done to help secure your use of Skype.
Automatic login should be switched off. Be aware that chat history is by default recorded on your computer (this is not encrypted) and have a look at how to switch this option off and how to delete already recorded messages. Be aware that Skype allows you to login with the same account details from several different computers at the same time. Change your password. Authenticate a Skype friend before having a conversation with them
Tip: One of the ongoing problems with instant messaging (and email for that reason) is authenticity. Apart from video conferencing or voice calls you may have no other way to authenticate whether the conversing party really is the person they are claiming to be. In these instances, it is advised to enquire personal information to help establish identity.