CryptologiaPub Date : 2022-01-26DOI: 10.1080/01611194.2022.2026840
Chris Christensen
{"title":"Review of The Bombe: The Machine that Defeated Enigma by Dermot Turing","authors":"Chris Christensen","doi":"10.1080/01611194.2022.2026840","DOIUrl":"https://doi.org/10.1080/01611194.2022.2026840","url":null,"abstract":"","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"46 1","pages":"385 - 386"},"PeriodicalIF":0.6,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48166538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2022-01-20DOI: 10.1080/01611194.2021.1998810
O. Ostwald, Frode Weierud
{"title":"Modern cryptanalysis of the Truppenschlüssel","authors":"O. Ostwald, Frode Weierud","doi":"10.1080/01611194.2021.1998810","DOIUrl":"https://doi.org/10.1080/01611194.2021.1998810","url":null,"abstract":"Abstract Truppenschlüssel (troop cipher) was a manual cipher used by the German Army during World War II. Based on more than a hundred authentic messages that survived the war, a cryptanalysis is performed. The exact encryption procedure is investigated via two plaintext-ciphertext compromises. A specific ciphertext-only breaking tool is developed, utilizing the hill climbing technique. This leads to successful breaks of most of the messages.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"261 - 281"},"PeriodicalIF":0.6,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44093533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2022-01-12DOI: 10.1080/01611194.2021.2003913
Stuart Boersma
{"title":"Elizebeth Smith Friedman and one example of a prohibition era encryption system","authors":"Stuart Boersma","doi":"10.1080/01611194.2021.2003913","DOIUrl":"https://doi.org/10.1080/01611194.2021.2003913","url":null,"abstract":"Abstract A short ciphertext message encrypted using a Prohibition era encryption system is examined. First published in David Kahn’s The Codebreakers, this example appears in two early reports written by Elizebeth Smith Friedman. Some obvious and some not so obvious errors are identified and corrected when possible. Friedman’s cryptanalysis of the ciphertext is given.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"227 - 238"},"PeriodicalIF":0.6,"publicationDate":"2022-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45039648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2022-01-11DOI: 10.1080/01611194.2021.1994486
K. Ahmed, S. Pal, R. Mohan
{"title":"A review of the tropical approach in cryptography","authors":"K. Ahmed, S. Pal, R. Mohan","doi":"10.1080/01611194.2021.1994486","DOIUrl":"https://doi.org/10.1080/01611194.2021.1994486","url":null,"abstract":"Abstract In this article, we survey and analyze the role of tropical semirings in key-exchange protocols proposed in the past decade. We also present new ideas on cryptanalysis of some tropical key agreement techniques suggested during this period.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"63 - 87"},"PeriodicalIF":0.6,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44725681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2022-01-10DOI: 10.1080/01611194.2021.1996484
G. Lasry
{"title":"Analysis of a late 19th century french cipher created by Major Josse","authors":"G. Lasry","doi":"10.1080/01611194.2021.1996484","DOIUrl":"https://doi.org/10.1080/01611194.2021.1996484","url":null,"abstract":"Abstract Rémi Géraud-Stewart and David Naccache have recently discovered historical documents from the late 19th century, written by Major H.D. Josse of the French Army, that describe a proposal for a new cipher. In our paper, we provide an in-depth analysis of the cipher and a revised formal description of the cipher based on the examples given by Josse. We also present classes of cryptologically equivalent keys, and a possible attack based on ciphertext isomorphs, that can be implemented with only pen-and-paper. We also describe a new ciphertext-only stochastic attack, based on simulated annealing, that can recover the key and the plaintext from ciphertexts with only 75 letters. We are planning to implement the cipher in CrypTool 2, an e-learning platform for cryptography.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"48 - 62"},"PeriodicalIF":0.6,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44048490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2021-12-28DOI: 10.1080/01611194.2021.1998809
Eugen Antal, Pavol Zajac
{"title":"The first Czechoslovak cipher machine","authors":"Eugen Antal, Pavol Zajac","doi":"10.1080/01611194.2021.1998809","DOIUrl":"https://doi.org/10.1080/01611194.2021.1998809","url":null,"abstract":"Abstract The Štolba cipher machine was the first Czechoslovak cipher machine used in the army after the mid-1930s, and later in Slovakia during WW2. It had a unique design based on pneumatic transmission and complex stepping rules. We present basic facts about the Štolba machine from documents found in Czech and Slovak archives. Although the machine description was incomplete (and in some cases not accurate), we have been able to reconstruct (a highly probable) encryption algorithm, and develop a method to reconstruct (message) key from a known PC pair. Part of the machine configuration, however, still remains unknown due to the large space of possible settings and the complexity of the algorithm.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"239 - 260"},"PeriodicalIF":0.6,"publicationDate":"2021-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42944556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2021-12-16DOI: 10.1080/01611194.2021.2002977
P. Anderson
{"title":"Review of Crypto Wars—The Fight for Privacy in the Digital Age: A Political History of Digital Encryption","authors":"P. Anderson","doi":"10.1080/01611194.2021.2002977","DOIUrl":"https://doi.org/10.1080/01611194.2021.2002977","url":null,"abstract":"","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"285 - 298"},"PeriodicalIF":0.6,"publicationDate":"2021-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44951320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2021-12-16DOI: 10.1080/01611194.2021.1989522
G. Lasry
{"title":"Cracking SIGABA in less than 24 hours on a consumer PC","authors":"G. Lasry","doi":"10.1080/01611194.2021.1989522","DOIUrl":"https://doi.org/10.1080/01611194.2021.1989522","url":null,"abstract":"Abstract The SIGABA was an electromechanical encryption device used by the US during WWII and in the 1950s. Also known as ECM Mark II, Converter M-134-C, CSP-889, and CSP-2900, the SIGABA was considered highly secure and was employed for strategic communications, such as between Churchill and Roosevelt. The SIGABA encrypts and decrypts with a set of five rotors and implements irregular stepping with two additional sets of five rotors. Its full keyspace, as used during WWII on some circuits, was in the order of It is believed that the German codebreaking services were unable to make any inroads into the cryptanalysis of SIGABA. The most efficient modern attack on SIGABA published so far is a known-plaintext attack that requires at least steps and extensive computing power. In this paper, the author presents a novel divide-and-conquer known-plaintext attack that can recover the key in less than 24 hours on a high-end consumer PC, taking advantage of multiple weaknesses in the design of SIGABA. With this attack, the author solved several series of full-keyspace challenges.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"1 - 37"},"PeriodicalIF":0.6,"publicationDate":"2021-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46956824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2021-12-16DOI: 10.1080/01611194.2021.1992686
Paul W. Relkin
{"title":"Solving the Olum 2 cipher: a new approach to cryptanalysis of transposition ciphers","authors":"Paul W. Relkin","doi":"10.1080/01611194.2021.1992686","DOIUrl":"https://doi.org/10.1080/01611194.2021.1992686","url":null,"abstract":"Abstract Olum 2 is one of two ciphers created more than 75 years ago by mathematician Paul Olum to challenge his Manhattan Project officemate, physicist Richard Feynman. In this manuscript, I describe the first successful decryption of Olum 2 using a novel approach to cryptanalysis of transposition ciphers. To decrypt Olum 2, I generated the bigrams and trigrams for all possible transposition intervals. I then identified transposition intervals with multiple bigrams and trigrams that occur frequently in English. I calculated the ratios of their English frequencies to the frequencies of bigrams and trigrams generated by a random reordering of the ciphertext. This enabled me to identify letter sequences with the highest probability of being true cipher message components rather than occurring by chance. In Olum 2, Professor Olum divided the message into sections of thirty-five letters and applied a rotating key to change the order of transposition for each successive section. His strategy not only confounded Professor Feynman but also proved impervious to several decryption programs in use today that assume a uniform transposition has been applied throughout the cipher. The decryption methods described in this manuscript can assist in the decryption of other ciphers employing a variety of transposition methods.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"47 1","pages":"38 - 47"},"PeriodicalIF":0.6,"publicationDate":"2021-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46051318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CryptologiaPub Date : 2021-12-07DOI: 10.1080/01611194.2021.1920070
N. Courtois, M. Grajek
{"title":"On latin squares, invariant differentials, random permutations and historical Enigma rotors","authors":"N. Courtois, M. Grajek","doi":"10.1080/01611194.2021.1920070","DOIUrl":"https://doi.org/10.1080/01611194.2021.1920070","url":null,"abstract":"Abstract In this article we study the quality of permutations in historical cipher machines from Germany, Spain, Italy, Norway, Switzerland, Japan, Hungary, Croatia, Poland, Czechoslovakia, Russia and the United States. We show that numerous real-life rotors have been made in order to imitate or tend to a certain ideal property related to latin squares. Rotors from the same source and the same period have consistent properties deeply rooted in classical cryptography of polyalphabetical ciphers. We demonstrate this based on probabilities: random occurrence of permutations having such features is unlikely, or would amount to winning in a lottery several times in row. We put all this in the context of known historical sources on how cipher machines and cryptanalysis have developed on both German and Allied sides. We also exhibit strong linear and differential properties. The same occurs in Fialka cipher machines. Finally, a stronger property holds for the historical block cipher T-310.","PeriodicalId":55202,"journal":{"name":"Cryptologia","volume":"46 1","pages":"387 - 421"},"PeriodicalIF":0.6,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46302331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}