Definition: secret key cryptography

An encryption method that uses the same secret key to encrypt and decrypt messages. The problem with this method is transmitting the secret key to a legitimate person who needs it. Contrast with "public key cryptography," which uses a two-part key; one public and one private. Very often, the public key method is used to transmit the secret key to the other party. For details on both methods, see cryptography. See encryption algorithm.

                Encrypt       Decrypt
 Secret Key
  Cryptography  Private key   Private key

 Public Key     Private key   Public key
  Cryptography  Public key    Private key