AuthenticationAuthentication is the process by which a user gains entry access to SQL Server. Microsoft supports two modes of authentication for MS SQL Server including Windows and Mixed modes. Windows mode enables Windows authentication using the Windows OS user credentials.

Mixed mode enables Windows and SQL Server authentication to be utilized for user credential access.EncryptionEncryption is the process of converting normal data into a code with the intent to protect the underlying the information from unauthorized viewing and protects the data in the event of unintended access. SQL Server supports the use of a certificate or key store to manage encrypting and decrypting data. Several of the encryption algorithms supported by SQL Server are DES, RC2, 128-bit RC4. These are implemented via the Windows Crypto API managed and supported by Microsoft.AuthorizationAuthorization pertains primarily to the process of authorizing users to access data and perform certain actions within the database environment. In SQL Server development an important authorization concept is least privilege.

This involves breaking administrative tasks down into specific defined roles and limiting authorized actions to those defined roles with no additional access that isn’t a hard requirement to perform the actions. By authorizing user roles to perform specific actions this limits security risk.Change TrackingChange Tracking when enabled allows the SQL Server Database Engine to store change information that occurs within tables in the database. The changes are tracked each time a T-SQL commit is performed. Snapshots can be taken which as you would expect take a virtual snapshot of what the database looks like and be used for recovery purposes if something goes awry with subsequent changes or commits.

A Sync Framework can also be used to track database changes and update data to remote data clients.