is it secure to send windows password via netNamedPipe

Question

Hello,

I don't know, is it secure to send windows password via netNamedPipeBinding to WCF service running on windows service? Hence, I request your thoughts on this and here is the scenario

We are asking the user to enter the windows user name and password from client application and sending them to WCF service(without explicit encryption) since the service need to interact with network mapped drive but currently we are not sure whether .net takes care of encrypting the user name and password and sends it via pipe or not.

About service details,

1. It uses the netNamedPipeBinding because we wanted this to be within machine level scope

2. Security mode set to mode="Transport" inthe config file

3. Transport protectionLevel set to protectionLevel="EncryptAndSign" inthe config file

4. There is no app.config at client side but creating object by passing "NetNamedPipeSecurityMode.Transport" "new NetNamedPipeBinding(NetNamedPipeSecurityMode.Transport)"

5. The machine where the wcf service is hosted may or may not be connected to internet

Is these enough? Or should I use explicit encryption? If explicit encryption required then, how to do?

Thanks, Sudhakar