Cisco Systems 2.5 Data and address integrity without encryption (AH)

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Cisco Router and Security Device Manager 2.5 User’s Guide
OL-4015-12
Chapter17 IP Security
Transform Set
Encryption
Cisco SDM recognizes the following ESP encryption types:
•ESP_DES. Encapsulating Security Payload (ESP), Data Encryption Standard
(DES). DES supports 56-bit encryption.
•ESP_3DES. ESP, Triple DES. This is a stronger form of encryption than DES,
supporting 168-bit encryption.
•ESP_AES_128. ESP, Advanced Encryption Standard (AES). Encryption with
a 128-bit key. AES provides greater security than DES and is computationally
more efficient than 3DES.
•ESP_AES_192. ESP, AES encryption with a 192-bit key.
•ESP_AES_256. ESP, AES encryption with a 256-bit key.
•ESP_SEAL—ESP with the 160-bit encryption key Software Encryption
Algorithm (SEAL) encryption algorithm. SEAL (Software Encryption
Algorithm) is an alternative algorithm to software-based Data Encryption
Standard (DES), Triple DES (3DES), and Advanced Encryption Standard
(AES). SEAL encryption uses a 160-bit encryption key and has a lower
impact to the CPU when compared to other software-based algorithms.
•ESP_NULL. Null encryption algorithm, but encryption transform used.
Note The types of ESP encryption available depend on the router. Depending on the
type of router you are configuring, one or more of these encryption types may not
be available.
Data and address integrity without encryption (AH)
This check box and the fields below it appear if you click Show Advanced.
Check this box if you want the router to provide Authentication Header (AH) data
and address integrity. The authentication header will not be encrypted.
Integrity Algorithm
Select one of the following:
•AH_MD5_HMAC—Message Digest 5.
•AH_SHA_HMAC—Security Hash Algorithm.