Computer Security and Cryptography

About the Cover: The term cipher alphabet is used when referring to a monoalphabetic substitution. When text is written using the letters A, B, …, Z, a cipher alphabet is a permutation or rearrangement of the 26 letters. In the fifteenth century, cryptography became more sophisticated and cryptographers proposed using multiple cipher alphabets, a process referred to as polyalphabetic substitution. Blaise de Vigenère's book A Treatise on Secret Writing published in the sixteenth century contains the basic Vigenère tableux, specifying the ciphertext in polyalphabetic substitution. Rotor machines introduced in the 20th-century provided mechanical means for implementing and speeding up polyalphabetic substitution.

The cover is a modified set of 17 cipher alphabets; the black background color is symbolic of the U.S. State Department's Black Chamber in which American cryptanalysis originated in the early part of the 20th-century. It is technically defective in several aspects (i) fewer than 26 letters in each row are displayed and (ii) repeated letters occur in the rows containing the word CRYPTOGRAPHY and my name.

Nevertheless, the cover hopefully projects the message to read Computer Security and Cryptography.

Copyright © 2007 by John Wiley & Sons, Inc. All rights reserved

Published by John Wiley & Sons, Inc., Hoboken, New JerseyPublished simultaneously in Canada

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