Security for Microsoft® Visual Basic® .NET

Private Key Encryption

While hash digests are useful for one-way encryption, when you need to decrypt the encrypted information, you need to use two-way encryption. The most common two way-encryption technique is key-based encryption. A key is simply a unique string that you pass together with a plain-text message to an encryption algorithm, which returns the message encrypted as cipher text. The cipher text bears no resemblance to the original message. To decrypt the cipher text, you again pass the key with the cipher text to a decryption algorithm, which returns the original plain-text message.

The most common type of key-based encryption is private key encryption, also called symmetric, traditional, shared-secret, secret-key, or conventional ...