Page 415 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

algorithms.

Be able to explain the basic operational modes of the Data
Encryption Standard (DES) and Triple DES (3DES). The Data

Encryption Standard operates in five modes: Electronic Code Book
(ECB) mode, Cipher Block Chaining (CBC) mode, Cipher Feedback
(CFB) mode, Output Feedback (OFB) mode, and Counter (CTR) mode.
ECB mode is considered the least secure and is used only for short
messages. 3DES uses three iterations of DES with two or three

different keys to increase the effective key strength to 112 or 168 bits,
respectively.

Know the Advanced Encryption Standard (AES). The
Advanced Encryption Standard (AES) uses the Rijndael algorithm and
is the U.S. government standard for the secure exchange of sensitive
but unclassified data. AES uses key lengths of 128, 192, and 256 bits
and a fixed block size of 128 bits to achieve a much higher level of

security than that provided by the older DES algorithm.