I would like to implement simple WCF along with security username and password. Client could be on Windows / Unix platform. I can send you my web.config where i have mentioned the validator class inside which i have a validate method to validate the username and password credentials. I am using custom binding. However i am receiving an error 'Could not establish trust relationship with SSL/TLS. Is there a simple way to implement WCF security with UN and PWD. Thanks in advance for any help.