15 February 1999:
Entire manual may be downloaded in tar-compressed PDF format:
http://jya.com/fm.tgz (3,619K). Thanks to MC.

28 December 1997
Thanks to JM

Entire manual may be downloaded in self-extracting, compressed PDF format:
http://jya.com/fm/fm34-40-2.exe (3,668K)

BASIC CRYPTANALYSIS

	FM 34-40-2 13 SEPTEMBER 1990
By Order of the Secretary of the Army:
	CARL E. VUONO General, United States Army Chief of Staff
Official:
THOMAS F. SIKORA Brigadier General, United States Army The Adjutant General
DISTRIBUTION: Active Army, USAR, and ARNG: To be distributed in accordance with DA Form 12-11E, requirements for FM 34-40-2, Basic Cryptanalysts, (Qty rqr block no. 4607) and FM 34-3, Intelligence Analysis (Qty rqr block no, 1119).
	U.S. GOVERNMENT PRINTING OFFICE; 1990-729/952

PREFACE

This field manual is intended as a training text in basic cryptanalytics and as a reference for cryptanalysts in military occupational specialty (MOS) 98C and related MOSs.

The proponent of this publication is Headquarters, United States Army Training and Doctrine Command (TRADOC). Send comments and recommendations on DA Form 2028 (Recommended Changes to Publications and Blank Forms) directly to Commander, United States Army Intelligence School, Fort Devens (USAISD), ATTN: ATSI-ETD-PD, Fort Devens, MA 01433-6301.

INTRODUCTION

This manual presents the basic principles and techniques of cryptanalysts and their relation to cryptography. Cryptography concerns the various ways of protecting messages from being understood by anyone except those for whom the messages are intended. Cryptographers are the people who create and use codes and ciphers. Cryptanalytics is the art and science of solving unknown codes and ciphers. Cryptanalysts try to break the codes and ciphers created and used by cryptographers.

This publication is organized into six parts. Part One explains basic principles which apply to all the parts that follow. The following five parts each cover a major type of system and the cryptanalytic techniques that apply to it. Parts Two, Three, and Four each build on the techniques explained in the parts that precede them. A new student should study these in order. Parts Five and Six are largely independent of Parts Two through Four and can be used separately after Part One.

For practice in the techniques explained in this manual, the Army Correspondence Course Program offers a course in basic cryptanalysts. See the References Section at the back of this manual for further information.

[Contents by JYA; links are to PDF files]

AUTHORIZATION (10K, see above)
PREFACE (8K, see above)
INTRODUCTION (16K, see above)

PART ONE Introduction to Cryptanalyst

CHAPTER 1 -- TERMINOLOGY AND SYSTEM TYPES (25K)
CHAPTER 2 -- SECURITY OF CRYPTOGRAPHIC SYSTEMS (130K)

PART TWO Monographic Substitution Systems

CHAPTER 3 -- MONOALPHABETIC UNILATERAL SUBSTITUTION SYSTEMS USING STANDARD CIPHER ALPHABETS (139K)
CHAPTER 4 -- MONOALPHABETIC UNILATERAL SUBSTITUTION SYSTEMS USING MIXED CIPHER ALPHABETS (536K)
CHAPTER 5 -- MONOALPHABETIC MULTILITERAL SUBSTITUTION SYSTEMS (413K)

PART THREE Polygraphic Substitution Systems

CHAPTER 6 -- CHARACTERISTICS OF POLYGRAPHIC SUBSTITUTION SYSTEMS (310K)
CHAPTER 7 -- SOLUTION OF POLYGRAPHIC SUBSTITUTION SYSTEMS (277K)

PART FOUR Polyalphabetic Substitution Systems

CHAPTER 8 -- PERIODIC POLYALPHABETIC SUBSTITUTION SYSTEMS (219K)
CHAPTER 9 -- SOLUTION OF PERIODIC POLYALPHABETIC SYSTEMS (686K)
CHAPTER 10 -- APERIODIC POLYALPHABETIC CIPHERS (290K)

PART FIVE Transposition Systems

CHAPTER 11 -- TYPES OF TRANSPOSITION SYSTEMS (77K)
CHAPTER 12 -- SOLUTION OF NUMERICALLY-KEYED COLUMNAR TRANSPOSITION CIPHERS (97K)
CHAPTER 13 -- TRANSPOSITION SPECIAL SOLUTIONS (76K)

PART SIX Analysis of Code Systems

CHAPTER 14 -- TYPES OF CODE SYSTEMS (77K)
CHAPTER 15 -- ANALYSIS OF SYLLABARY SPELLING (26K)

APPENDIX E -- UTILITY TABLES (266K)
APPENDIX F -- CRYPTANALYSIS SUPPORT PROGRAM (578K)
See HTML version of Appendix F with machine-readable program: http://jya.com/appf.htm (28K)

GLOSSARY (9K)
REFERENCES (8K)
INDEX (250K)