Microsoft® SQL Server 2008 R2 Unleashed

An Overview of Data Encryption

Encryption is the process of obfuscating data by the use of a key or password. This can make the data useless without the corresponding decryption key or password. Encryption does not solve access control problems. However, it enhances security by limiting data loss even if access controls are bypassed.

Encryption is actually the conversion of readable plaintext into ciphertext, which cannot be easily understood by unauthorized people. The concrete procedure of carrying out the encryption is called an algorithm. Decryption is the process of converting ciphertext back into its original form so it can be understood. Both encryption and decryption require a key, which must be kept secret because it enables the holder ...