**Here's the scenario:**

When a document is created within a specific document library, a workflow will be started. This workflow will require the document owner to select a number of users to be either primary agents or secondary agents for the document.

The workflow will then create fine grain permissions for that document for both the secondary and primary agents. These will be the only users able to see the document in the library.

Am I on the right track here in terms of thinking this is best achieved with implementing fine-grain permissions?

Would this be difficult to implement using a workflow created in SharePoint designer? Or would I have to implement something more custom in Visual Studio?

I thought that before I try to implement something, I should put the question out there as there is bound to be someone with more experience with this kind of thing than me.

Any advice is much appreciated.