Developing Secure Applications with Visual Basic

Generating Symmetric Keys

For most circumstances in which you'll be encrypting and decrypting data, you'll be using symmetric encryption, primarily because symmetric encryption is much faster than asymmetric encryption. This speed makes symmetric encryption much more practical for most applications today. After two applications have agreed on a symmetric encryption key, they can freely exchange encrypted messages with a minimum of overhead.

Symmetric encryption keys also are very practical for single application needs. A symmetric encryption key can be derived from a hash of any string or object. Thus, you can derive a symmetric key from the hash of a user password and use it to protect files or other sensitive files from other computer users. ...