ZyXEL Vantage CNM User Guide - Page 333

Chapter 11 IPSec VPN Table 131 Device Operation > Device Configuration > VPN > IPSec VPN > VPN Connection > Add/Edit (Manual Key) (continued) LABEL DESCRIPTION Encryption Algorithm This field is applicable when the Active Protocol is ESP. Select which key size and encryption algorithm to use in the IPSec SA. Choices are: NULL - no encryption key or algorithm DES - a 56-bit key with the DES encryption algorithm 3DES - a 168-bit key with the DES encryption algorithm AES128 - a 128-bit key with the AES encryption algorithm AES192 - a 192-bit key with the AES encryption algorithm AES256 - a 256-bit key with the AES encryption algorithm The ZyWALL and the remote IPSec router must use the same algorithm and key. Longer keys require more processing power, resulting in increased latency and decreased throughput. Authentication Select which hash algorithm to use to authenticate packet data in the Algorithm IPSec SA. Choices are SHA1 and MD5. SHA1 is generally considered stronger than MD5, but it is also slower. The ZyWALL and remote IPSec router must use the same algorithm. Vantage CNM User's Guide 333