Motorola Wireless Broadband Platform manual Data Encryption Standard DES, Key/Number, Description

Key/Number	Description
Session Key	The session key is calculated separately by the
	SM and the BAM, using the Authentication
	Key, the ESN, and the random number. This
	key is sent to the AP by the BAM – like the
	other keys, it never goes over the air. The
	network operator or the subscriber never sees
	this key. This key is either 56 bits (DES) or
	128 bits (AES) in length.
Random Number	A random number is generated by the BAM
	and used during each attempt by an SM to
	register and authenticate. The subscriber or
	network operator never sees this number. This
	is a 128 bit number.

Of the three numbers presented in Table 2, only the Authentication Key is settable by the network operator and it must be set both in the BAM and in the SM. Further information about Canopy’s authentication process is detailed in Bandwidth and Authentication (BAM) User Guide.

ENCRYPTION

The Canopy system also has provisions for the industry-accepted DES with key management via the Telecommunications Industry Association (TIA) standard BRAID cryptosystem. In addition, the Canopy system provides for AES for customers who require the most secure networks available. These encryption techniques are transparent to network firewalls, Dynamic Host Configuration Protocol (DHCP) servers and Network Address Translation (NAT) devices.

Data Encryption Standard (DES)

DES is an encryption standard that uses an encryption technique developed in the mid 1970s by IBM and then adopted by the Federal government as a federal standard in 1977 for protecting sensitive, but not classified data. DES was designed so that even if someone knows some of the plain text data and the corresponding ciphertext, there is no way to determine the key without trying all possible keys. The strength of DES encryption based security rests on the size of the key and the proper protection of the key.1 The following paragraphs discuss details of DES from the document entitled, Federal Information Processing Standards (FIPS) PUB 46-3 Data Encryption Standard (DES):

The Data Encryption Standard (DES) specifies two Federal Information Processing Standards (FIPS) approved cryptographic algorithms as required by FIPS 140-1. Encrypting data converts it to an unintelligible form called cipher.

1Security Complete, Adapted from Active Defense, by Chris Brenton with Cameron Hunt.

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