6.1. Do You Really Need Encryption?6.1.1. What Should Be Protected?6.1.2. What Are You Protecting Against?6.2. SQL Server 2008 Encryption Key Hierarchy6.2.1. The Automatic Key Management Hierarchy6.2.1.1. Symmetric Keys, Asymmetric Keys, and Certificates6.2.1.2. Database Master Key6.2.1.3. Service Master Key6.2.2. Alternative Encryption Management Structures6.2.2.1. Symmetric Key Layering and Rotation6.2.2.2. Removing Keys from the Automatic Encryption Hierarchy6.2.2.3. Extensible Key Management6.3. Data Protection and Encryption Methods6.3.1. Hashing6.3.2. Symmetric Key Encryption6.3.3. Asymmetric Key Encryption6.3.4. Transparent Data Encryption6.4. Balancing Performance and Security6.5. Implications of Encryption on Query Design6.5.1. Equality Matching Using Hashed Message Authentication Codes6.5.2. Wildcard Searches Using HMAC Substrings6.5.3. Range Searches6.6. Summary