Here’s a fun paper: “The Naibbe cipher: a substitution cipher that encrypts Latin and Italian as Voynich Manuscript-like ciphertext“: > Abstract: In this article, I investigate the hypothesis that the Voynich > Manuscript (MS 408, Yale University Beinecke Library) is compatible with being > a ciphertext by attempting to develop a historically plausible cipher that can > replicate the manuscript’s unusual properties. The resulting cipher­a verbose > homophonic substitution cipher I call the Naibbe cipher­can be done entirely > by hand with 15th-century materials, and when it encrypts a wide range of > Latin and Italian plaintexts, the resulting ciphertexts remain fully > decipherable and also reliably reproduce many key statistical properties of > the Voynich Manuscript at once. My results suggest that the so-called > “ciphertext hypothesis” for the Voynich Manuscript remains viable, while also > placing constraints on plausible substitution cipher structures...

In the early 1960s, National Security Agency cryptanalyst and cryptanalysis instructor Lambros D. Callimahos coined the term “Stethoscope” to describe a diagnostic computer program used to unravel the internal structure of pre-computer ciphertexts. The term appears in the newly declassified September 1965 document Cryptanalytic Diagnosis with the Aid of a Computer, which compiled 147 listings from this tool for Callimahos’s course, CA-400: NSA Intensive Study Program in General Cryptanalysis. The listings in the report are printouts from the Stethoscope program, run on the NSA’s Bogart computer, showing statistical and structural data extracted from encrypted messages, but the encrypted messages themselves are not included. They were used in NSA training programs to teach analysts how to interpret ciphertext behavior without seeing the original message...

Well, this is interesting: > The auction, which will include other items related to cryptology, will be > held Nov. 20. RR Auction, the company arranging the sale, estimates a winning > bid between $300,000 and $500,000. > > Along with the original handwritten plain text of K4 and other papers related > to the coding, Mr. Sanborn will also be providing a 12-by-18-inch copper plate > that has three lines of alphabetic characters cut through with a jigsaw, which > he calls “my proof-of-concept piece” and which he kept on a table for > inspiration during the two years he and helpers hand-cut the letters for the > project. The process was grueling, exacting and nerve wracking. “You could not > make any mistake with 1,800 letters,” he said. “It could not be repaired.”...

The NSA and GCHQ have jointly published a history of World War II SIGINT: “Secret Messengers: Disseminating SIGINT in the Second World War.” This is the story of the British SLUs (Special Liaison Units) and the American SSOs (Special Security Officers).

Interesting article—with photos!—of the US/UK “Combined Cipher Machine” from WWII.