GCHQ Christmas Codebreaking Challenge
Looks like fun.
Details here.
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Category Archives: history of cryptography
Mary Queen of Scots Letters Decrypted
This is a neat piece of historical research.
The team of computer scientist George Lasry, pianist Norbert Biermann and astrophysicist Satoshi Tomokiyo—all keen cryptographers—initially thought the batch of encoded documents related to Italy, because that was how they were filed at the Bibliothèque Nationale de France.
However, they quickly realised the letters were in French. Many verb and adjectival forms being feminine, regular mention of captivity, and recurring names—such as Walsingham—all put them on the trail of Mary. Sir Francis Walsingham was Queen Elizabeth’s spymaster…
Charles V of Spain Secret Code Cracked
Diplomatic code cracked after 500 years:
In painstaking work backed by computers, Pierrot found “distinct families” of about 120 symbols used by Charles V. “Whole words are encrypted with a single symbol” and the emperor replaced vowels coming after consonants with marks, she said, an inspiration probably coming from Arabic.
In another obstacle, he used meaningless symbols to mislead any adversary trying to decipher the message.
The breakthrough came in June when Pierrot managed to make out a phrase in the letter, and the team then cracked the code with the help of Camille Desenclos, a historian. “It was painstaking and long work but there was really a breakthrough that happened in one day, where all of a sudden we had the right hypothesis,” she said…
Gus Simmons’s Memoir
Gus Simmons is an early pioneer in cryptography and computer security. I know him best for his work on authentication and covert channels, specifically as related to nuclear treaty verification. His work is cited extensively in Applied Cryptography.
He… Continue reading Gus Simmons’s Memoir
History of the HX-63 Rotor Machine
Jon D. Paul has written the fascinating story of the HX-63, a super-complicated electromechanical rotor cipher machine made by Crypto AG.
Continue reading History of the HX-63 Rotor Machine
More Military Cryptanalytics, Part III
Late last year, the NSA declassified and released a redacted version of Lambros D. Callimahos’s Military Cryptanalytics, Part III. We just got most of the index. It’s hard to believe that there are any real secrets left in this 44-year-old … Continue reading More Military Cryptanalytics, Part III
Newly Declassified NSA Document on Cryptography in the 1970s
This is a newly unclassified NSA history of its reaction to academic cryptography in the 1970s: “NSA Comes Out of the Closet: The Debate over Public Cryptography in the Inman Era,” Cryptographic Quarterly, Spring 1996, author still classifi… Continue reading Newly Declassified NSA Document on Cryptography in the 1970s
The Story of Colossus
Nice video of a talk by Chris Shore on the history of Colossus.
Continue reading The Story of Colossus
Military Cryptanalytics, Part III
The NSA has just declassified and released a redacted version of Military Cryptanalytics, Part III, by Lambros D. Callimahos, October 1977.
Parts I and II, by Lambros D. Callimahos and William F. Friedman, were released decades ago — I believe repeatedly, in increasingly unredacted form — and published by the late Wayne Griswold Barker’s Agean Park Press. I own them in hardcover.
Like Parts I and II, Part III is primarily concerned with pre-computer ciphers. At this point, the document only has historical interest. If there is any lesson for today, it’s that modern cryptanalysis is possible primarily because people make mistakes…
Enigma Machine Recovered from the Baltic Sea
Neat story:
German divers searching the Baltic Sea for discarded fishing nets have stumbled upon a rare Enigma cipher machine used by the Nazi military during World War Two which they believe was thrown overboard from a scuttled submarine.
Thinking the… Continue reading Enigma Machine Recovered from the Baltic Sea