Transparent Data Encryption (TDE) encrypts the data within the physical files of the database, the 'data at rest'. Without the original encryption certificate and master key, the data cannot be read when the drive is accessed or the physical media is stolen. The data in unencrypted data files can be read by restoring the files to another server. TDE requires planning but can be implemented without changing the database. Robert Sheldon explains how to implement TDE.
Aaron Bertrand (@AaronBertrand) revisits the impact that eliminating DONE_IN_PROC messages using SET NOCOUNT ON may or may not have on query performance
There are several ways to implement encryption in SQL Server; Arshad Ali focuses on Transparent Data Encryption (TDE), which was introduced in SQL Server 2008 and is available in later releases.