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Modes of Operation for DES

Electronic Code Book mode (ECB)
$\includegraphics {des-ecb.eps}$
Not very secure -- too susceptible to frequency analysis. No feedback.
Cypher Block Chaining (CBC)
$\includegraphics {des-cbc.eps}$
More secure. Nonlinear feedback. Need M_i to get started.
Output Feedback Mode (OFB)
$\includegraphics {des-ofb.eps}$
Nonlinear feedback; similar to nonlinear feedback shift register. Very fast -- can prepare all but the C_i in advance. Key material eventually repeats. No mixing.
Cypher Feedback Mode (CFB)
$\includegraphics {des-cfb.eps}$
More secure but need M_i to get started. Nonlinear feedback. (Very similar to CBC.)

About this document ...

Modes of Operation for DES

This document was generated using the LaTeX2HTML translator Version 97.1 (release) (July 13th, 1997)

The command line arguments were:
latex2html -link 0 -split +0 des-modes.tex.

The translation was initiated by Joshua Holden on 10/30/2000

Joshua Holden
10/30/2000