Codebreaking by Elonka Dunin and Klaus Schmeh -- Read -- Imperial Library of Trantor

Index

Cover Title Copyright Contents Preface 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 shall I do? What tools do I need for codebreaking? How can I encrypt my files and emails? I have a comment on this book; what shall I do? Who contributed to this book?

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 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

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

Frequency analysis Guessing frequent words Guessing words with unusual letter patterns

Success stories

How Gary Klivans broke a prison inmate 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

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 and word guessing 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

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

How André Langie broke a 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

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) 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 second message (Z340) The Zodiac Killer’s third message (Z13) The Zodiac Killer’s fourth message (Z32) The Scorpion cryptograms Henry Debosnys’ messages

7. Codes and nomenclators

Codes

The difference between codes and ciphers

Nomenclators Terminology The history of codes and nomenclators Super-encryption 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 Lord Franklin’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

8. Polyalphabetic ciphers

How a polyalphabetic cipher works

Vigenère cipher 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 attack 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

9. Complete columnar transposition ciphers

How complete columnar transposition ciphers work How to detect a complete columnar transposition 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 11th ciphergram Edgar Allan Poe’s first challenge Some IRA messages

10. Incomplete columnar transposition ciphers

How an incomplete columnar transposition works How to detect an incomplete columnar transposition How to break an incomplete columnar transposition Success stories

Kryptos – K3 Antonio Marzi’s radio messages

Challenges

Another IRA message The Double Columnar Transposition Reloaded challenge

Unsolved cryptograms

The Catokwacopa ad series

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 solution of a turning grille André Langie’s solution of a turning grille Karl de Leeuw’s solution of a turning grille The Mathias Sandorf cryptogram

Challenges

The Friedmans’ Christmas card Jew-Lee and Bill’s Cryptocablegram A MysteryTwister C3 challenge A Kerckhoffs cryptogram

12. Digraph substitution

How a digraph substitution works

General case Playfair cipher

How to detect a digraph substitution

General case Detection of a Playfair cipher

How to break a digraph substitution

Frequency analysis Dictionary attack Manual attack on the Playfair cipher

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

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 Tamam Shud mystery Two unsolved postcards

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

15. Additional encryption methods

Cipher tools Voice encryption Code talking Shorthand (stenography) Hidden messages (steganography)

Success story: How Elonka found a hidden message on a tombstone Success story: Deciphering Steganographia Challenge: Mysterious Stranger message Success story: Another steganographic message by the Friedmans

Cipher machines

16. Solving ciphers with hill climbing

Solving simple substitution ciphers with hill climbing

Success story: Bart Wenmecker’s solution of the Baring-Gould cryptogram Success story: The Florida murder case cryptogram

Solving a homophonic cipher with hill climbing

Success story: Dhavare, Low and Stamp’s Zodiac Killer solutions

Solving a Vigenère cipher with hill climbing

Success story: Jim Gillogly’s solution of IRA Vigenère cryptograms

Solving a columnar transposition with hill climbing

Success story: Jim Gillogly’s solution of IRA transposition cryptograms Success story: Richard Bean’s solution of the last unsolved IRA cryptogram Success story: George Lasry’s solution of the double columnar transposition challenge

Solving a turning grille cipher with hill climbing

Success story: Bart Wenmeckers’ solution of a turning grille cryptogram Success story: Armin Krauß’s solution of a turning grille challenge

Solving a general digraph substitution with hill climbing

Success story: Some digraph challenges

Solving a Playfair cipher with hill climbing

Success story: Dan Girard’s solution of the Cheltenham Letter Stone Success story: Some Playfair challenges

Solving machine ciphers with hill climbing

Success story: Breaking original Enigma messages

17. What next?

More unsolved cryptograms

The fourth Kryptos message (K4) The Rubin cryptogram Ricky McCormick’s encrypted notes The carrier pigeon message from the Second World War Even more unsolved cryptograms

Codebreaking tools Other books about codebreaking Websites about codebreaking Journals and newsletters Events

Appendix A: Kryptos

K1 K2 K3 K4

Appendix B: Useful language statistics

Letter frequencies Most frequent digraphs Most frequent doubled letters Most frequent trigraphs Most frequent words Average word lengths in a text Index of coincidence

Appendix C: Glossary Appendix D: Figure sources References Index

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