Symmetric Encryption - Software
A type of encryption where the same key is used to encrypt and decrypt the message. This differs from asymmetric (or public-key) encryption, which uses one key to encrypt a message and another to decrypt the message. A common example of this is known as the Caeser 13 key. It simply takes as input a sentence and shifts the letters up by 13 in the alphabet and wraps around when going from Z over to A. To decrypt a message, you can simply use the same 13 letter shift that you did to encrypt the message.