Brother International MFC-J815DW XL Online Users Guide HTML - Page 457

Option Encapsulating Security Description communication. Therefore, it is necessary to identify the applicable SA when an IPsec packet is received. The SPI parameter, which identifies the SA, is included in the Authentication Header (AH) and Encapsulating Security Payload (ESP) header. These settings are necessary when Custom is selected for Use Prefixed Template, and Manual is selected for Internet Key Exchange (IKE). Enter the In/Out values. (3-10 characters) • Protocol Select ESP or AH. - ESP is a protocol for carrying out encrypted communication using IPsec. ESP encrypts the payload (communicated contents) and adds additional information. The IP packet is comprised of the header and the encrypted payload, which follows the header. In addition to the encrypted data, the IP packet also includes information regarding the encryption method and encryption key, the authentication data, and so on. - AH is part of the IPsec protocol that authenticates the sender and prevents manipulation of the data (ensures the completeness of the data). In the IP packet, the data is inserted immediately after the header. In addition, the packets include hash values, which are calculated using an equation from the communicated contents, secret key, and so on, in order to prevent the falsification of the sender and manipulation of the data. Unlike ESP, the communicated contents are not encrypted, and the data is sent and received as plain text. • Encryption Select DES, 3DES, AES-CBC 128, or AES-CBC 256. • Hash Select None, MD5, SHA1, SHA256, SHA384, or SHA512. None can be selected only when ESP is selected in Protocol. • SA Lifetime Specify the IKE SA lifetime. Type the time (seconds) and number of kilobytes (KByte). • Encapsulation Mode Select Transport or Tunnel. • Remote Router IP-Address Type the IP address (IPv4 or IPv6) of the remote router. Enter this information only when the Tunnel mode is selected. SA (Security Association) is an encrypted communication method using IPsec or IPv6 that exchanges and shares information, such as the encryption method and encryption key, in order to establish a secure communication channel before communication begins. SA may also refer to a virtual encrypted communication channel that has been established. The SA used for IPsec establishes the encryption method, exchanges the keys, and carries out mutual authentication according to the IKE (Internet Key Exchange) standard procedure. In addition, the SA is updated periodically. 450