title: Design Patterns for security and data access control
body: <p>Having recently discovered design patterns, and having acquired the excellent Head First Design Patterns book (can really recommend it!), I am now wondering about design patterns for security and controlling access to records in data stores.</p>
  
  <p>My use case is a bespoke CRM style application, with contacts, businesses, and users who have different levels of access, including being limited to read only access, or even a subset of records.  I will only be doing distinct entity level access control, not field level.</p>
  
  <p>Can anyone recommend any security orientated design patterns that would fit the above?</p>
  
  <p>If it makes a difference, I am using ASP.Net MVC, Entity Framework 4 and SQL Server 2008.</p>