Login And Messaging Security

Hey i was doing a research about login and messaging security in today's app like viber,whatsapp,twitter,facebook,skype to know how they protect our information during login on our phones and while we are sharing messages, but i found this topic is rarely discussed and didnt found information on most of these apps,while i found this topic should be very important for each one of us.
So i am asking for your help if anyone know anything about this subject.
Thanks in advance.

 

Hello Ronjor and thanks for replying,
i did a quick search over the sub forum but i didnt found what im looking for.
i would like for example to know what does viber security mechanism for login and how our messages are encrypted .
if you think that the thread should be moved to privacy technology section please do
thanks again.