Microsoft® Windows® 2000 Security Handbook

Types of Encryption

I have spent most of the chapter so far discussing a lot of the history and mechanics of cryptography. Now, it's time to discuss some of the specifics. Begin by looking at the two main types of encryption available today.

Private Key Cryptography

In private key (also called symmetric key) cryptography, a single key is used for both encryption and decryption. This process is illustrated in Figure 8.1.

Figure 8.1. An example of private key encryption

The encryption example at the beginning of the chapter was an example of a private key algorithm because to encrypt or decrypt the message, you needed the same key. Private key ...