Codebreaking A Practical Guide 1st Edition by Elonka Dunin, Klaus Schmeh ISBN 1718502729 9781718502727

Chapter 1: How Can I Break an Encrypted Message? And Other Introductory Questions

• What is this book about?
• Which technical terms do I need to know?
• How can I break an encrypted text?
• How do I know what kind of encryption I am dealing with?
• I have found an encrypted text in the attic; can you decipher it for me?
• I have encrypted a text myself; can you break it?
• I have invented a new encryption method; can you take a look at it?
• I have solved a famous unsolved cryptogram; what should I do?
• What tools do I need for codebreaking?
• How can I encrypt my files and email?
• I have a comment on this book; what should I do?
• Who contributed to this book?

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Chapter 2: The Caesar Cipher

• How the Caesar cipher works
• How to detect a Caesar cipher
• How to break a Caesar cipher
• Success Stories
  • A prison inmate’s cipher
  • A spy’s encrypted sheet
  • An encrypted journal from the movie The Prestige
• Challenges
  • Herbert Yardley’s first challenge
  • A series of newspaper advertisements from 1900

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Chapter 3: Simple Substitution Ciphers

• How simple substitution ciphers work
• How to detect a simple substitution cipher
• Example of a cipher that is not a simple substitution cipher
• Index-of-coincidence technique
• How to break a simple substitution cipher
• Performing a frequency analysis
• Guessing frequent words
• Guessing words with unusual letter patterns
• Success Stories
  • How Gary Klivans broke a prison inmate’s code
  • How Kent Boklan broke encrypted diary entries from the Civil War
  • Beatrix Potter’s diary
• Challenges
  • A prison code
  • A postcard
  • Another postcard
  • The Friedmans’ wedding centennial nickel
  • An Aristocrat from the ACA
  • Unsolved cryptograms
  • An encrypted newspaper ad from 1888
  • The Zodiac Celebrity Cypher
  • The Furlong postcard

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Chapter 4: Simple Substitution Ciphers Without Spaces Between Words: Patristocrats

• How a Patristocrat, a simple substitution cipher without spaces, works
• How to detect a Patristocrat
• How to break a Patristocrat
• Frequency analysis using digraphs
• Word guessing
• Success Stories
  • A prison message
  • The Cheltenham Number Stone
• Challenges
  • Rudyard Kipling’s encrypted message
  • NSA’s second Monday Challenge
  • Unsolved cryptograms
  • The Dorabella cryptogram
  • The Chinese gold bars mystery
  • James Hampton’s notebook

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Chapter 5: Simple Substitution Ciphers in Non-English Languages

• Detecting the language used
• How to break a non-English simple substitution cipher
• Frequency analysis and word guessing
• Word pattern guessing
• Success Stories
  • A girl’s pigpen cipher (Spanish)
  • The La Buse cryptogram (French)
  • A postcard with a love message (German)
  • A Mafia message (Italian)
• Challenges
  • An encrypted postcard
  • The third NSA Monday Challenge
  • Christlieb Funk’s challenge cryptogram
  • Unsolved cryptograms
  • The Voynich manuscript
  • The cigarette case cryptogram
  • NSA’s fourth Monday Challenge
  • The Moustier altar inscriptions

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Chapter 6: Homophonic Ciphers

• How homophonic ciphers work
• How to detect a homophonic cipher
• How to break a homophonic cipher
• Success Stories
  • The first Zodiac message (Z408)
  • The Zodiac Killer’s second message (Z340)
  • Ferdinand III’s letters
  • A postcard from Hawaii
• Challenges
  • A message to the Zodiac Killer
  • Edgar Allan Poe’s second challenge
  • Unsolved cryptograms
  • Beale Papers #1 and #3
  • The Zodiac Killer’s third message (Z13)
  • The Zodiac Killer’s fourth message (Z32)
  • The Scorpion cryptograms
  • Henry Debosnys’s messages

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Chapter 7: Codes and Nomenclators

• Codes
• Nomenclators
• Terminology
• The history of codes and nomenclators
• Superencryption of codes and nomenclators
• How to detect a code or nomenclator
• How to break a code or nomenclator
• Finding the nomenclator table or codebook
• Exploiting weaknesses of codes and nomenclators
• Solving codes and nomenclators with cribs
• Success Stories
  • A telegram sent to Tel Aviv
  • Encrypted messages by Mary, Queen of Scots
  • Collinson’s search expedition
  • The Japanese JN-25 code
• Challenges
  • The Mount Everest telegram
  • Unsolved cryptograms
  • The silk dress cryptogram
  • The train station robbery cryptogram
  • A Pollaky newspaper advertisement
  • Lord Manchester’s letter

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Chapter 8: Polyalphabetic Ciphers

• How a polyalphabetic cipher works
• Vigenère cipher
• Other polyalphabetic ciphers
• One-time pad
• How to detect a polyalphabetic cipher
• How to break a polyalphabetic cipher
• Word guessing
• Checking for repeating patterns (Kasiski’s method)
• Using the index of coincidence
• Dictionary attacks
• Tobias Schrödel’s method
• Other Vigenère breaking methods
• How to break a one-time pad
• Success Stories
  • The Diana Dors message
  • Kryptos 1 and 2
  • The Cyrillic Projector
  • Thouless’s second cryptogram from the crypt
  • The Smithy Code
• Challenges
  • The Schooling challenge
  • A German radio message from the Second World War
  • Unsolved cryptograms
  • Wood’s cryptogram from the crypt

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Chapter 9: Complete Columnar Transposition Ciphers

• How complete columnar transposition ciphers work
• How to detect a complete columnar transposition cipher
• How to break a complete columnar transposition cipher
• The arrange-and-read method
• Vowel frequencies and multiple anagramming
• Success Stories
  • Donald Hill’s diary
  • The Pablo Waberski spy case
• Challenges
  • The Lampedusa message
  • The Friedmans’ love messages
  • An encrypted “agony” ad
  • Yardley’s eleventh ciphergram
  • Edgar Allan Poe’s first challenge
  • An IRA message

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Chapter 10: Incomplete Columnar Transposition Ciphers

• How an incomplete columnar transposition cipher works
• How to detect an incomplete columnar transposition cipher
• How to break an incomplete columnar transposition cipher
• Success Stories
  • Kryptos K3
  • Antonio Marzi’s radio messages
• Challenges
  • Yet another IRA message
  • The Double Columnar Transposition Reloaded challenge
  • Unsolved cryptograms
  • The Catokwacopa ad series

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Chapter 11: Turning Grille Transposition Ciphers

• How turning grille encryption works
• How to detect a turning grille encryption
• How to break a turning grille encryption
• Success Stories
  • Paolo Bonavoglia’s turning grille solution
  • André Langie’s turning grille solution
  • Karl de Leeuw’s turning grille solution
  • The Mathias Sandorf cryptogram
• Challenges
  • The Friedmans’ Christmas card
  • Jew-Lee and Bill’s Cryptocablegram
  • A MysteryTwister challenge
  • A Kerckhoffs cryptogram

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Chapter 12: Digraph Substitution

• How general digraph substitution works
• How the Playfair cipher works
• How to detect a general digraph substitution
• How to detect a Playfair cipher
• How to break a digraph substitution
• Frequency analysis
• Dictionary attacks
• Manual attacks
• Success Stories
  • Thouless’s first message
  • Thouless’s third message
• Challenges
  • The cryptogram in National Treasure: Book of Secrets
  • Unsolved cryptograms
  • The world record digraph challenge
  • The world record Playfair challenge

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Chapter 13: Abbreviation Ciphers

• How abbreviation ciphers work
• How to detect an abbreviation cipher
• How to break an abbreviation cipher
• Success Stories
  • Emil Snyder’s booklet
• Challenges
  • A birthday card
  • Unsolved cryptograms
  • The Tamám Shud mystery
  • Two unsolved postcards

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Chapter 14: Dictionary Codes and Book Ciphers

• How dictionary codes and book ciphers work
• How to detect a dictionary code or book cipher
• How to break a dictionary code or book cipher
• Identifying the book or dictionary
• Reconstructing the dictionary
• Treating a book cipher like a simple substitution cipher
• Success Stories
  • The FIDES ads
  • Nicholas Trist’s key book
  • How William Friedman broke a Hindu conspiracy encryption
  • A dictionary code message sent to Robert E. Lee
• Challenges
  • Dan Brown’s book cipher challenge
  • A dictionary code challenge
  • Unsolved cryptograms
  • Two encrypted newspaper advertisements from 1873

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Chapter 15: Additional Encryption Methods

• Cipher tools
• Voice encryption
• Code talking
• Shorthand (stenography)
• Hidden messages (steganography)
• Success Stories
  • How Elonka found a hidden message on a tombstone
  • Deciphering Steganographia
  • Mysterious Stranger message
• Challenge
  • Another steganographic message by the Friedmans
• Cipher machines

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Chapter 16: Solving Ciphers with Hill Climbing

• Solving simple substitution ciphers with hill climbing
• Simulated annealing
• Success Stories
  • Bart Wenmeckers’s solution to the Baring-Gould cryptogram
  • The Florida murder case cryptogram
  • Solving a homophonic cipher with simulated annealing
  • Solving a Vigenère cipher with hill climbing
  • Solving a columnar transposition with hill climbing
  • Solving a turning grille cipher with hill climbing
  • Solving a general digraph substitution with hill climbing
  • Solving a Playfair cipher with hill climbing
  • Solving machine ciphers with hill climbing

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Chapter 17: What Next?

• More unsolved cryptograms
• The fourth Kryptos message (K4)
• The Rubin cryptogram
• Ricky McCormick’s encrypted notes
• The carrier pigeon message from World War II
• The encrypted NKRYPT pillars
• Even more unsolved cryptograms
• Codebreaking Tools
• Other books about codebreaking
• Websites about codebreaking
• Journals and newsletters