Published: 2019-06-12
ISBN: 978-91-7685-087-9
ISSN: 1650-3686 (print), 1650-3740 (online)
This paper describes the current progress of our research in the area of breaking homophonic substitution ciphers. Furthermore, it presents the state-of-the-art of cryptanalyzing this kind of cipher. There is a huge gap between the success rate of methods published in according research papers and the success rate of already available tools on the Internet. This paper also presents a small general taxonomy of monoalphabetic substitution ciphers. Finally, it shows how we broke different homophonic substitution ciphers in an automatic as well as in a semi-automatic way.
automatic cryptanalysis
semi-automatic cryptanalysis
homophonic substitution ciphers
hillclimbing
simulated annealing
fixed temperature
DECRYPT project
CrypTool 2
Citta del Vaticano Archivio Segreto Vaticano. 2019. Archivum Secretum Vacticanum, http://www.archiviosegretovaticano.va/.
Fco Alberto Campos, Alberto Gascón, Jesús María Latorre, and J Ramón Soler. 2013. Genetic Algorithms and Mathematical Programming to Crack the Spanish Strip Cipher. Cryptologia, 37(1):51-68.
Thang Dao. 2008. Masters Thesis: Analysis of the Zodiac 340-Cipher.
Amrapali Dhavare, Richard M Low, and Mark Stamp. 2013. Efficient Cryptanalysis of Homophonic Substitution Ciphers. Cryptologia, 37(3):250---281.
David Kahn. 1996. The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet. Simon and Schuster.
John C King and Dennis R Bahler. 1993. An algorithmic solution of sequential homophonic ciphers. Cryptologia, 17(2):148-165.
Nils Kopal, Olga Kieselmann, Arno Wacker, and Bernhard Esslinger. 2014. CrypTool 2.0. Datenschutz und Datensicherheit-DuD, 38(10):701-708.
Nils Kopal. 2018. Solving Classical Ciphers with CrypTool 2. In Proceedings of the 1 st International Conference on Historical Cryptology HistoCrypt 2018, number 149, pages 29-38. Linkoping University Electronic Press.
George Lasry. 2018a. A Methodology for the Cryptanalysis of Classical Ciphers with Search Metaheuristics. kassel university press GmbH.
George Lasry. 2018b. Deciphering German Diplomatic and Naval Attache Messages from 1914-1915. In Proceedings of the 1 st International Conference on Historical Cryptology HistoCrypt 2018, number 149, pages 55-64. Linkoping University Electronic Press.
Beata Megyesi, Kevin Knight, and Nada Aldarrab. 2017. DECODE - Automatic Decryption of Historical Manuscripts. http://stp.lingfil.uu.se/-bea/decode/.
MTC3. 2018. MysteryTwister C3 The Crypto Challenge Contest, https://www.mysterytwisterc3.org/.
David Oranchak. 2008. Evolutionary Algorithm for Decryption of Monoalphabetic Homophonic Substitution Ciphers Encoded as Constraint Satisfaction Problems. In Proceedings of the 10th annual conference on Genetic and evolutionary computation, pages 1717-1718. ACM.
Sujith Ravi and Kevin Knight. 2011. Bayesian Inference for Zodiac and other Homophonic Ciphers. In Proceedings of the 49thAnnual Meeting of the Association for Computational Linguistics: Human Language Technologies-Volume 1, pages 239-247. Association for Computational Linguistics.
Luis Alberto Benthin Sanguino, Gregor Leander, Christof Paar, Bernhard Esslinger, and Ingo Niebel. 2016. Analyzing the Spanish Strip Cipher by Combining Combinatorial and Statistical Methods. Cryptologia, 40(3):261-284.
José Ramón Soler Fuensanta and Francisco Javier López-Brea Espiau. 2007. The Strip Cipher-The Spanish Official Method. Cryptologia, 31(1):46-56.
Satoshi Tomokiyo. 2018. How I reconstructed a Spanish cipher from 1591. Cryptologia, 42(6):477--484.
Zodiac Killer Ciphers ZKC. 2019. Webpage and wiki, http://zodiackillerciphers.com/.
