Prototype authentication and user account subsystem for web

We require the development of the prototype authentication and user account subsystem for our web service. Initially we are looking to build a prototype to integrate with other prototype subsystems. The initial work will also help to develop a specification for a production version. We are looking for a developer with previous experience developing relatively high performance and secure but not unnecessarily complex user account/authentication subsystem. For this early work we suggest an hourly rate is more appropriate than a fixed price as the scope of the work will be subject to change during this early phase. Developers with whom we can strike up a good working relationship will be invited to bid for later stages of the work. The back end subsystem will need to interact with receiving servers written in Twisted or Node.js handling real time data received from iphones and android phones with a web service developed using the Django web framework. Requirements - fairly immediate availability – no more than a few days delay. - Must have solid experience building secure user authentication subsystem - Must have experience in MySQL / Django. All code and intellectual property is to be owned by us. Further details Will require regular (daily updates and availability for phone discussion during protoyping phase). All variable naming, comments and technical reports to be completed in *good* English. We are not necessarily looking for a development house – proposals are most certainly welcome for experienced "one man bands". Above all we are looking for technical competence at this stage. Development to be done under signed NDA. We look for proposals particularly laying out experience in the areas mentioned and any initial thoughts about how you would go about the protoyping.