WS security peoplesoft IB

1) For inbound process from third party to peoplesoft, we need to restrict the data flow in Integration Broker based on the external application credentials. In case if we enable the WS Security in external node then how which will work because in node level we are giving the external user id and password and in which the password is encrypted. 2) For outbound process how that we can share the data through IB using external user id and password authentication.