I don't believe you would need to reset the cache on a production server, it is not a best practice to perform in this case. Most of the times in development or test environments for the purpose of benchmarking you would need to reset the cache for optimum results. You may know that in this case...
When I had a chance to know about encryption features in SQL Server I always go with books online as a first hand information, but there is more to ask about this feature in 2005 version: Have you ever thought about encryption in SQL Server, how to implement it? What you need to know to implement cryptographic...