Cisco Systems OL-24201-01 manual GL-6

Glossary

D

daemon

DES

A program which is often started at the time the system boots and runs continuously without intervention from any of the users on the system. The daemon program forwards the requests to other programs (or processes) as appropriate. The term daemon is a Unix term, though many other operating systems provide support for daemons, though they're sometimes called other names. Windows, for example, refers to daemons and System Agents and services.

Data Encryption Standard. A widely-used method of data encryption using a private (secret) key. There are 72,000,000,000,000,000 (72 quadrillion) or more possible encryption keys that can be used. For each given message, the key is chosen at random from among this enormous number of keys. Like other private key cryptographic methods, both the sender and the receiver must know and use the same private key.

datagram	Request for Comment 1594 says, "a self-contained, independent entity of data carrying sufficient
	information to be routed from the source to the destination computer without reliance on earlier
	exchanges between this source and destination computer and the transporting network." The term has
	been generally replaced by the term packet. Datagrams or packets are the message units that the
	Internet Protocol deals with and that the Internet transports. A datagram or packet needs to be
	self-contained without reliance on earlier exchanges because there is no connection of fixed duration
	between the two communicating points as there is, for example, in most voice telephone
	conversations. (This kind of protocol is referred to as connectionless.)
decapsulation	The process of stripping off one layer's headers and passing the rest of the packet up to the next higher
	layer on the protocol stack.
decryption	The process of transforming an encrypted message into its original plaintext.
denial of service	The prevention of authorized access to a system resource or the delaying of system operations and
	functions.
device	Capability to control and audit the administration operations performed on network devices. The
administration	network device administrator role has full access to perform the administrative operations on network
	devices.
dictionaries	A store to configure attributes of RADIUS and TACACS+ protocols, internal users, and internal hosts.
dictionary attack	An attack that tries all of the phrases or words in a dictionary, trying to crack a password or key. A
	dictionary attack uses a predefined list of words compared to a brute force attack that tries all possible
	combinations.
Diffie-Hellman	A key agreement algorithm published in 1976 by Whitfield Diffie and Martin Hellman.
	Diffie-Hellman does key establishment, not encryption. However, the key that it produces may be used
	for encryption, for further key management operations, or for any other cryptography.

Digest Authentication

digital certificate

Allows a web client to compute MD5 hashes of the password to prove it has the password.

An electronic "credit card" that establishes your credentials when doing business or other transactions on the Web. It is issued by a certification authority. It contains your name, a serial number, expiration dates, a copy of the certificate holder's public key (used for encrypting messages and digital signatures), and the digital signature of the certificate-issuing authority so that a recipient can verify that the certificate is real.

	User Guide for Cisco Secure Access Control System 5.3
GL-6	OL-24201-01