In SQL Server 2005, column-level (sometimes called cell-level) encryption became available. Now, encryption could occur within the database, but it was not easy to use, offered poor performance, and it required a re-architecture of the application, along with changes to the database schema. Even with these downsides, column-level encryption offered some advantages: such as granular security; data is encrypted in memory and disk; and explicit key management, which allows different users to protect their own data using their own keys, even preventing the DBA from seeing a user’s data. Even so, the disadvantages were so great that only the most sensitive columns of a table were generally encrypted, which meant that much of the data in a database was still left unencrypted