Computer-agnostic codebreaking books

  • Helen Fouché Gaines: Cryptanalysis (1939): This work is a classic and probably the most successful book about codebreaking ever written. Today it is outdated, as it was created before the computer age, but it is still filled with valuable information for anyone interested in codebreaking techniques.

  • André Langie: Cryptography (1922): Great book that explains the ciphers and codebreaking methods of its time in an easy-to-understand way.
  • William Friedman: Military Cryptanalysis, Parts I-IV (ca. 1938): Friedman’s widely used work delivers a scientific approach to codebreaking on over 1000 pages. Friedman is considered the most famous cryptologist in history, the person who even coined the terms “cryptanalysis” and “index of coincidence”.
  • Andreas Figl: Systeme des Chiffrierens (“Systems of Encipherment”; Volume 1: 1926, Volume 2: 1927): Written by a World War I Austrian codebreaker, in German. Though this book is outdated, it is, along with Gaines’ Cryptanalysis, one of the best and most comprehensive codebreaking books of the pre-computer era.
  • U.S. Department of the Army: Basic Cryptanalysis (1990): Field manual about breaking simple substitution ciphers, polyalphabetic ciphers and transpositions. It is available for free on the internet.
  • Solomon Kullback: Statistics in Cryptanalysis (1976): This codebreaking book focuses on codebreaking with statistics, such as frequency analysis and the index of coincidence.
  • Parker Hitt: Manual for the solution of military ciphers (1916): Compact codebreaking work published by the Press of the Army Service Schools that covers simple substitution, polyalphabetic ciphers, transpositions, and Playfair.
  • Abraham Sinkov: Elementary Cryptanalysis (1966): Codebreaking book that follows a mathematical approach.

Codebreaking books that include computer-based solving techniques

  • Robert Reynard: Secret Code Breaker. A Cryptanalyst’s Handbook (1996): This 90-page book has a very basic introduction to cryptanalysis, and mentions a number of computer programs from the time, though few of these are still relevant today.
  • George Lasry: A Methodology for the Cryptanalysis of Classical Ciphers with Search Metaheuristics (2018): George Lasry’s PhD thesis about breaking manual and machine ciphers with hill climbing and other methods.
  • Al Sweigart: Cracking Codes with Python (2018): Introduces many algorithms for implementing and breaking manual ciphers. Also covers modern cryptography.

Books about cryptanalysis of computer-based methods

  • Mark Stamp, Richard M. Low: Applied Cryptanalysis: Breaking Ciphers in the Real World (2007)
  • Antoine Joux: Algorithmic Cryptanalysis (2009)

Other books that include information about codebreaking

  • David Kahn: The Codebreakers (1st ed., 1967; 2nd ed., 1996). This is the classic among the books about crypto history. As the title implies, it is more about the people who were codebreakers (and codemakers) than about codebreaking. Nevertheless, it is a must-read for everybody interested in cryptanalysis and the encryption methods of the last 4000 years.

  • Bernhard Esslinger & CrypTool team: Learning and Experiencing Cryptography with CrypTool and SageMath (2018). Free book that contains interesting information about classical encryption systems and how they can be broken with free software.
  • Craig Bauer: Secret History – The Story of Cryptology (2013). Combines the history of cryptology with mathematical descriptions of historical crypto algorithms.

  • Craig Bauer: Unsolved! (2017). A well-researched book about famous unsolved crypto mysteries; includes a great deal of information about codebreaking.
  • Simon Singh: The Code Book (1999). Bestseller about the history of encryption. Some codebreaking techniques are explained.

  • Simon Singh: The Cracking Code Book (2002). Based on The Code Book, this work gives an entry-level introduction to codebreaking, mainly for children. Some editions are titled The Code Book for Young People.
  • Friedrich Bauer: Decrypted Secrets (2006). A classic (the first edition was published in 1993) that describes historical and modern encryption algorithms, along with cryptanalysis.
  • Denise Sutherland, Mark Koltko-Rivera: Cracking Codes & Cryptograms for Dummies (2011): Despite the promise of the title, only about 10% of this book is actually about codebreaking, but it still can be of interest because it has a large number of puzzles to solve.

Cryptography books for kids

Aside from our own book, we recommend:

  • Simon Singh: The Code Book Adapted for Young Adults (2003, 274 pages). This is an abbreviated version adapted for young adults of the original New York Times bestseller The Code Book. This work is mainly about the history of ciphers and provides some entry-level information about codebreaking.
  • Herbert Zim: Codes and Secret Writng (1948, 154 pages): Was the classic read for children in the 1950s and 1960s. Briefly covers some history, substitution ciphers, and an introduction to secret writing, including invisible ink.
  • Martin Gardner: Codes, Ciphers and Secret Writing (1972, 96 pages): Good for elementary school students and scouts. Gives an overview on many basic encryption systems.
  • Jean Daigneau: Code Cracking for Kids (2019, 144 pages): Includes hands-on activities for kids.

Books written by Elonka

Aside from Codebreaking: A Practical Guide, Elonka has written
  • Elonka Dunin: The Mammoth Book of Secret Codes and Cryptograms (2006). Over 400 code and puzzles, along with a great deal of information about unsolved cryptograms.

  • Daniel Burstein, Arne de Keijzer: Secrets of the Lost Symbols (2009). Elonka contributed two chapters about Kryptos to this anthology, which delves into the real history of the hidden meanings behind Dan Brown’s number one best-selling novel The Lost Symbol.

Books written by Klaus

Aside from Codebreaking: A Practial Guide, Klaus has written:


  • Klaus Schmeh: Cryptography (2002). A comprehensive introduction to modern cryptography.


  • Chief Security Officer (2018)
  • Versteckte Botschaften (2017)
  • Kryptografie – Verfahren, Protokolle, Infrastrukturen  (2016)

  • Codeknacker gegen Codemacher (2014)
  • Nicht zu knacken (2012)
  • Die Erben der Enigma (2011)
  • Elektronische Ausweisdokumente (2009)
  • Die Welt der geheimen Zeichen (2004)
  • Kryptografie und Public-Key-Infrastrukturen im Internet (2001)
  • Safer Net (1998)

German, not crypto-related:

  • Warum Gähnen ansteckend ist (2008)
  • Das trojanische Pferd (2007)
  • Planeten und Propheten (2006)
  • Titel, Tore, Transaktionen (2005)
  • Der Kultfaktor (2004)
  • David gegen Goliath (2004)
  • Top-Manager in 7 Tagen (2002)
  • Die 55 größten Flops der Wirtschaftsgeschichte (2001)

More crypto books

If you want to know more about books covering manual and machine-based encryption, check This website operated by codebreakers Tobias Schrödel and Nils Kopal describes over 500 titles from the last 600 years.