With data stored in tables, you have a few options to protect data. Check out this tip to learn more about column level encryption.
Beginning with SQL Server 2005, column-level encryption and decryption capabilities were made available within the database, providing a solution for situations where one-off types of data need to be secured beyond your existing authorization, authentication or firewall settings. This article provides an overview and example of securing a column using native SQL Server cryptography functions.
I need to encrypt my data within SQL Server and I plan on using the built-in encryption functionality in SQL Server 2005 and 2008. However, I'm looking at symmetric and asymmetric key algorithms and while I see information saying to use symmetric keys, I don't understand why. What's the difference between the two and why is a symmetric key algorithm preferred over the asymmetric key ones?
Authenticators are additional data that gets encrypted along with the data to be stored in an encrypted manner. When it comes to decrypt the data, if the right authenticator isn't specified, SQL Server doesn't return the data in the decrypted form. Rather, a NULL value is returned, just as if the wrong key was used.