NT Service communication

Hello,

I want to create an "Object pool" NT Service. It will represent this:

Webserver --> Webservice --> NT Service --> RSA Class

Now, the part of the "Webservice --> NT Service" is the most tricky. I want the Webservice to communicate (like just referencing it as a Class) with the NT Service at the lowest possible overhead!

Does anyone know how to do this?

The idea of the whole setup is this:
An end-user visits a login page, there a few things must be entered to validate the user like login, password, pincode and an RSA token. The user clicks ok and the data is being transfered to the webserver. The webserver calls in a webservice on another (RSA) machine, which takes over the login data and passes it on to the NT Service. The NT Service holds an object pool for each user. The NT Service creates an RSA Class to communicate with the RSA Server. The RSA Server can respond with 3 possible values: 0, 1 or 2 (authenticated, not authenticated, authenticated but token must be reentered). When the return value is 2, the object in the NT Service must be pooled for another use, because the webserver will send a popup to the end user to recheck the code and enter it.

Hope you understand and thank you for your help.