Military Cryptanalysis

Friedman W.F.0894120646, 9780894120640

This book provides an excellent foundation for solving cipher systems. The text describes the fundamental principles of cipher solution plus use of the unilateral frequency distribution in the solution process is covered in some detail. Various unilateral and multilateral systems are carefully discussed. In addition, the text introduces the student to the solution of digraphic substitution ciphers, including the solution of the Playfair Cipher. Numerous problems are provided for solution by the student.

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Table of contents :
MILITARY CRYPTANALYSIS Part IV……Page 0
With Added PROBLEMS and COMPUTER PROGRAMS……Page 1
FOREWORD……Page 5
POLYALPHABETIC SUBSTITUTION SYSTEMS……Page 6
INTRODUCTORY REMARKS……Page 7
CIPHER ALPHABETS FOB POLYALPHABETIC SUBSTITUTION……Page 10
THEORY OF SOLUTION OF REPEATING-KEY SYSTEMS……Page 16
REPEATING-KEY SYSTEMS WITH STANDARD CIPHER ALPHABETS……Page 23
REPEATING-KEY SYSTEMS WITH MIXED CIPHER ALPHABETS, I……Page 30
REPEATING-KEY SYSTEMS WITH MIXED CIPHER ALPHABETS, II……Page 55
THEORY OF INDIRECT SYMMETRY OF POSITION IN SECONDARY ALPHABETS’……Page 58
APPLICATION OF PRINCIPLES OF INDIRECT SYMMETRY OF POSITION……Page 66
REPEATING-KEY SYSTEMS WITH MIXED CIPHER ALPHABETS,III……Page 84
BEPEATING-KEY SYSTEMS WITH MIXED CIPEEB ALPHABETS, IV……Page 90
Analytical Key for Military Cryptanalysis, Part II *……Page 101
THE 12 TYPES oF CIPHER SQUARES……Page 102
ELEMENTARY STATISTICAL THEOEY APPLICABLE TO TFIE PHENOMENA OB REPETITION……Page 114
A GRAPHICAL METHOD OF RECONSTRUCTING PRIMARY COMPONENTS BY……Page 127
INDEX……Page 138
PROBLEMS……Page 140
COMPUTER PROGRAMS……Page 154
INDEX OF PROGRAMS……Page 155
Vigenere Encipherment……Page 156
TRUE BEAUFORT ENCIPHERMENT……Page 158
VARIANT BEAUFORT ENCIPHERMENT……Page 160
DETERMINING THE PERIOD OF A PERIODIC CIPHER……Page 162
VIGENERE ENCIPHERMENT USING MIXED ALPHABETS……Page 164