Simple VB.Net OATH HOTP/TOTP application (ongoing work)

For this project I am only looking for programmers who are interested in ongoing work. This project is part of a larger programme of works to further develop our software and as this project ends another should begin. This work is to create a basic but fully functional Windows application that runs as a Windows service. This application needs to: 1. Be written in VB.Net 2. Listen on a TCP port for incoming connections. 3. Communicate using a protocol which you will document so that another programmer can write an application to send it commands. 4. Accept the inputs for a HOTP / TOTP calculation over the network. 5. Return the result of the calculation. 6. Allow for multiple client requests (incoming TCP connections) at any one time. OATH HOTP and TOTP are documented on Wikipedia and elsewhere (there are RFCs documenting this). So recapping - this is a) a network wrapper, b) some already documented maths calculations, c) the calculations returned to the network wrapper, d) documentation of your work. Testing will be carried out using the iPhone "OATH token" (Archie L. Cobbs) application (free) and (assuming the same counter and hexadecimal secret) your output should match the iPhone app's output. Obviously you need to provide a way to test your application. This could be via telnet or you could create a small application to send requests - the is up to you - we just need to be able to test it easily and sign off your work. Personally I'd make a small app to send data to the network service, but as I said, this is up to you. Documentation can be in notepad. Price is negotiable.