Which transfer security mode is best choice For the following conditions:
Service=asp.net mvc app Hosted on IIS to WSHttpBinding and persession instance mode.
Client=Wpf App (Desktop app)
One point here is that client by Internet connection Connected to the server.
If you mean WCF transport security, then your simplest choice is HTTPS. You can either buy a certificate to place on your service's IIS installation or you can create your own CA and sign your own certificate.
If you go for roll-your-own, then you should install your Certificate Authority on the end user's machine so that when the WPF app talks to the WCF service over https, it is part of the trust chain. If you work for an organisation, then this decision is usually left to the security/administrators, as they may not be comfortable with you simply creating your own CA. At the very least you may have to ask them to create one for you. Or they will tell you to buy one.
If you go for a buy-certificate approach, then assuming you buy it from one of the major providers, that certificate authority will already be trusted and you won't have to include a CA installation step as part of your desktop app installer/instructions.
Major SSL providers are Verisign, GlobalSign, etc.
StartSSL provide a free certificate.
