Nortel Networks 608(WL) - Manual (Page 131)

Chapter 4
Configuration via the Command Line Interface
E-DOC-CTC-20051017-0169 v0.1 129
Cryptographic function
[crypto]
The table below shows the cryptographic functions supported by the SpeedTouch™
along with their corresponding key size:
 DES is relatively slow and is the weakest of the algorithms, but it is the
industry standard.
 3DES is a stronger version of DES, but is the slowest of the supported
algorithms (for a comparable key length).
 AES is the new encryption standard selected by the American government to
replace DES/3DES. It is recommended to use AES since it is the most
advanced of the supported encryption methods.
 NULL encryption: The message is not encrypted. Selecting NULL encryption
achieves authentication without encryption, being equivalent to the use of the
Authentication Header (AH) that is no longer supported from Release 5.3
onwards.
In addition, NULL encryption may be useful for testing purposes since the
messages on the communication link can be interpreted. Message
authentication remains active.
Key length [keylen] The SpeedTouch™ supports 3 different key lengths for the AES encryption
algorithm. The
keylen parameter assigns the key length for this algorithm. Three
values are valid, as specified in the table above..
Authentication Hashing
function [integrity]
The SpeedTouch™ supports two types of hashing algorithms:
 HMAC is always used as integrity algorithm, combined with either MD5 or
SHA1.
 SHA1 is stronger than MD5, but slightly slower.
Algorithm Valid key sizes
(bits) Popular sizes Default size
DES 56 56 56
3DES 168 168 168
AES 128, 192, 256 128, 192, 256 -
NULL - - -
The DES and 3DES algorithms have a fixed key length. For these algorithms
the [keylen] parameter is not shown in the CLI.
Hashing algorithm
MD5
SHA1