Encryption is a method of encoding information in a way that it can only be read back in its original form by systems that have a key that allows decryption. The key required to decrypt the original information can be identical to the key used to encrypt it. This is known as Symmetric Key Encryption. Asymmetric encryption uses two keys to protect information. One key that is used to encrypt the information, and another key that is secret and is used to decrypt it. The popular Public Key Encryption method uses this approach. The key to encrypt information is public for any system to use, but the keys required to decrypt are private and only those with rights to access the information can use them. To find out more about how encryption works view the KEMP paper on TLS/SSL security