Security of data is a hot topic these days. One of the security concerns auditors have is whether or not your SQL Server data is encrypted when stored At-Rest–meaning auditors would like to see all data encrypted on the actual disk platters that store the data. By default, SQL Server does not encrypt data in a SQL Server database in an encrypted format. When SQL Server 2008 was introduced, Microsoft implemented Transparent Data Encryption (TDE).
When TDE is enabled on a database SQL Server will encrypt the database as data is written to the disk. Additionally, when data is read from disk it will be unencrypted. When data is in memory is it is in an unencrypted format.