SQL Server® 2008 Administration: Real World Skills for MCITP Certification and Beyond

Understanding Encryption

The process of converting data from its normal state to an unreadable state is known as encryption. The unreadable state is known as ciphertext (or cipherdata), and the readable state is plaintext (or plaindata). The normal way to encrypt something is to pass the data through an algorithm using a key for variable results. For example, say you want to protect the number 108. Here is an algorithm for protecting numeric data:

original data / crypto key + (3 x crypto key)

Using this algorithm to protect (encode or encrypt) the number 108 with a key of 3, you come up with this:

108 / 3 + (3 × 3) = 45

In order to recover the original data, you must know both the algorithm and the key. Needless to say, modern crypto algorithms ...