Military Cryptanalysis

Friedman W.F.0089412196

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
INTRODUCTORY……Page 6
SOLUTION OF SYSTEMS USING CONSTANT-LENGTH KEYING UNITS TO ENCIPHER……Page 10
SOLUTION OF SYSTEMS USING CONSTANT-LENGTH KEYING UNITS TO ENCIPHER……Page 13
SOLUTION OF SYSTEMS USING CONSTANT-LENGTH KEYING UNITS TO ENCIPHER……Page 19
SOLUTION OF SYSTEMS USING VARIABLE-LENGTH KEYING UNITS TO ENCIPHER……Page 24
REVIEW OF AUTO-KEY SYSTEMS……Page 33
SOLUTION OF CIPHER-TEXT AUTO-KEY SYSTEMS……Page 35
SOLUTION OF PLAIN-TEXT AUTO-KEY SYSTEMS……Page 50
METHODS OF LENGTHENING OR EXTENDING THE KEY……Page 55
GENERAL PRINCIPLES UNDERLYING SOLUTION OF SYSTEMS EMPLOYING LONG……Page 58
THE “COINCIDENCE” OR “x” TEST……Page 63
THE “CROSS-PRODUCT SUM” OR “x TEST”’……Page 78
APPLYING THE CROSS-PRODUCT SUM OR x TEST……Page 84
THE “MONOALPHABETICITY” OR “+ TEST”……Page 99
CONCLUDING REMARKS……Page 102
APPENDIX 1……Page 103
INDEX……Page 122
’ Analytical Key for Military Cryptanalysis, Part IlI……Page 124
BOOKS IN THE CRYPTOGRAPHIC SERIES……Page 125