There are four separate Advanced Encryption Standard (AES) Encryption Keys used for Tunneling. Connect Mode and Accept Mode contain their own sets of keys. One Key is used for encrypting outgoing data and the other Key is used for decrypting incoming data.

These AES Keys are a fixed 16 bytes in length. Any Keys entered that are less than 16 bytes long are padded with zeroes. Key data can be entered in as Text or Binary form. The Text form is a simple string of ASCII characters. Binary form is a string of characters representing byte values where each Hexadecimal byte value starts with \0x and each Decimal byte value starts with \.

Note that the Keys are shared secret keys so they must be known by both sides of the connection and kept secret.

Note that this device also supports SSH using AES Encryption as an alternative to secure tunneling. It is recommended that SSH be used because it does not require configuring shared secret keys and is a more secure standards based protocol. SSH.