Classical Cryptology

* Codes, ciphers, and codebreaking have been around for millennia, with the survival of nations sometimes hanging on the security of codes and ciphers. With modern computer networking, they have become important in day-to-day life. This document provides a technical and historical introduction to codes, ciphers, and codebreaking. A list of illustration credits is included at the end of this document.

[1.0] Introduction To Codes, Ciphers, & Codebreaking

• [1.1] BASIC CONCEPTS
  
• [1.2] SIMPLE SUBSTITUTION CIPHERS
  
• [1.3] SIMPLE TRANSPOSITIONS
  
• [1.4] FREQUENCY ANALYSIS AGAINST CIPHERS
  
• [1.5] CRACKING CODES / CODES VERSUS CIPHERS
  

[2.0] Refining The Art

• [2.1] CRYPTANALYSIS ARISES IN THE WEST
  
• [2.2] POLYALPHABETIC SUBSTITUTION CIPHERS / THE VIGENERE CIPHER
  
• [2.3] OTHER CIPHER REFINEMENTS
  
• [2.4] CIPHERS GO PUBLIC
  

[3.0] The Rise Of Field Ciphers

• [3.1] TELEGRAPHY & CRYPTOLOGY
  
• [3.2] CRACKING THE VIGENERE CIPHER
  
• [3.3] THE UNION ROUTE CIPHER / MULTIPLE ANAGRAMMING
  
• [3.4] POLYBIUS, BIFID, PLAYFAIR, & STRADDLING CHECKERBOARD CIPHERS
  
• [3.5] GRILLES & TURNING GRILLES
  

[4.0] Codes & Codebreakers In World War I

• [4.1] ROOM 40 & THE ZIMMERMANN TELEGRAM / GERMAN CODEBREAKERS
  
• [4.2] TRENCH CODES
  
• [4.3] GEORGES PAINVIN & THE ADFGX / ADFGVX CIPHERS
  
• [4.4] JOSEPH MAUBORGNE & THE ONE-TIME PAD CIPHER
  

[5.0] The Mechanization of Ciphers

• [5.1] CIPHER DISKS
  
• [5.2] THE BAZERIES CYLINDER
  
• [5.3] SCHERBIUS & THE ENIGMA
  
• [5.4] TELEPHONE SCRAMBLERS / SIGSALY
  

[6.0] US Codebreakers In The Shadow Of War

• [6.1] HERBERT O. YARDLEY & THE ORIGINS OF AMERICAN CRYPTANALYSIS
  
• [6.2] WILLIAM FRIEDMAN / US ARMY SIS
  
• [6.3] US NAVY OP-20-G
  
• [6.4] SIS CRACKS RED & PURPLE / CORAL & JADE
  
• [6.5] OP-20-G VERSUS JN-25
  
• [6.6] PEARL HARBOR
  

[7.0] US Codebreakers In World War II

• [7.1] CRACKING JN-25
  
• [7.2] THE SIS IN WORLD WAR II
  
• [7.3] THE US ECM MARK II CIPHER MACHINE
  
• [7.4] THE NAVAJO CODE-TALKERS
  
• [7.5] VENONA
  
• [7.6] ORIGINS OF THE NSA
  

[8.0] British Codebreakers In World War II

• [8.1] THE POLES CRACK ENIGMA
  
• [8.2] BLETCHLEY PARK & ULTRA
  
• [8.3] BLETCHLEY PARK AGAINST ENIGMA
  
• [8.4] THE AMERICAN CONNECTION
  
• [8.5] BLETCHLEY PARK CRACKS NAVAL ENIGMA
  
• [8.6] WINTERBOTHAM PUBLISHES THE ULTRA SECRET
  

[9.0] Lorenz & Colossus

• [9.1] TELECIPHER SYSTEMS
  
• [9.2] THE LORENZ SX-40/42 TELECIPHER MACHINES
  
• [9.3] HEATH ROBINSON & COLOSSUS
  
• [9.4] BORIS HAGELIN & THE M-209
  
• [9.5] COMMENTS, SOURCES, & REVISION HISTORY