When connecting to a server which has setup their SSL encryption with a self-signed certificate through a Java or an android app, you’ll get an SSLException since their certificate isn’t signed by a Certificate Authorities (CA) which is a 3rd party who is trusted by everyone. javax.net.ssl.SSLException: Not trusted server certificate exception If you have access to the server or know the site admin, get them to buy a CA signed SSL certificate. But in case that is not possible or feasible we can one thing we can do is configure our HTTP client library to just not verify the site hostname with the certificate. But then again that is not a good solution and defeats the whole purpose of encryption.