.NET Security

Hi all, I've got a .NET application where users authenticate using Form Authentication and then they're assigned to Admin or User roles. Admins are allowed to modify data and Users have read-only permissions. After data is modified I'd like Admins to be able to preview data in the new browser ...

When using ComputeSignature function I always end up with an error: The keyset is not defined. I am using SmartCard. Any explanation to this error ? public void Encrypt(string FileName)         {             string tempFile = Path.GetTempFileName(); ...