SQL2008 Cell Level Encryption

Question

Hi, I have an issue. I wanted to encrypt data in the sql db using cell level encryption on a table having > 1 Million rows. But tht column was clustered indexed and from web application we search the data based on the column. 

I heard there will lot of performance issues if we try to query a clustered index encrypted column. 

Please suggest.

As an alternative I have a thought, don't know if this is appropriate or not. Would it be possible to provide column level permission on the specific column to be encrypted to a specific user and make the database Transparent Database encrypted ? So that we shall write some .net component at front end to show data as encrypted and when searched it will be searched based upon privileged user who have access to this column. 

Please suggest.