Long Analysis of the M-209
Really interesting analysis of the American M-209 encryption device and its security.
Continue reading Long Analysis of the M-209
Collaborate Disseminate
Really interesting analysis of the American M-209 encryption device and its security.
Continue reading Long Analysis of the M-209
The NSA’s “National Cryptographic School Television Catalogue” from 1991 lists about 600 COMSEC and SIGINT training videos.
There are a bunch explaining the operations of various cryptographic equipment, and a few code words I have ne… Continue reading List of Old NSA Training Videos
Really interesting article on the ancient-manuscript scholars who are applying their techniques to the Voynich Manuscript.
No one has been able to understand the writing yet, but there are some new understandings:
Davis presented her findings at the medieval-studies conference and published them in 2020 in the journal Manuscript Studies. She had hardly solved the Voynich, but she’d opened it to new kinds of investigation. If five scribes had come together to write it, the manuscript was probably the work of a community, rather than of a single deranged mind or con artist. Why the community used its own language, or code, remains a mystery. Whether it was a cloister of alchemists, or mad monks, or a group like the medieval Béguines—a secluded order of Christian women—required more study. But the marks of frequent use signaled that the manuscript served some routine, perhaps daily function…
Interesting paper about a German cryptanalysis machine that helped break the US M-209 mechanical ciphering machine.
The paper contains a good description of how the M-209 works.
Continue reading Breaking the M-209
The Polish Embassy has posted a series of short interview segments with Marian Rejewski, the first person to crack the Enigma.
Details from his biography.
Continue reading Rare Interviews with Enigma Cryptanalyst Marian Rejewski
During the Cold War, the US Navy tried to make a secret code out of whale song.
The basic plan was to develop coded messages from recordings of whales, dolphins, sea lions, and seals. The submarine would broadcast the noises and a computer—the Combo Signal Recognizer (CSR)—would detect the specific patterns and decode them on the other end. In theory, this idea was relatively simple. As work progressed, the Navy found a number of complicated problems to overcome, the bulk of which centered on the authenticity of the code itself.
The message structure couldn’t just substitute the moaning of a whale or a crying seal for As and Bs or even whole words. In addition, the sounds Navy technicians recorded between 1959 and 1965 all had natural background noise. With the technology available, it would have been hard to scrub that out. Repeated blasts of the same sounds with identical extra noise would stand out to even untrained sonar operators…
Through a 2010 FOIA request (yes, it took that long), we have copies of the NSA’s KRYPTOS Society Newsletter, “Tales of the Krypt,” from 1994 to 2003.
There are many interesting things in the 800 pages of newsletter. There are many redactions. And a 1994 review of Applied Cryptography by redacted:
Applied Cryptography, for those who don’t read the internet news, is a book written by Bruce Schneier last year. According to the jacket, Schneier is a data security expert with a master’s degree in computer science. According to his followers, he is a hero who has finally brought together the loose threads of cryptography for the general public to understand. Schneier has gathered academic research, internet gossip, and everything he could find on cryptography into one 600-page jumble…
David Kahn has died. His groundbreaking book, The Codebreakers was the first serious book I read about codebreaking, and one of the primary reasons I entered this field.
He will be missed.
EDITED TO ADD (2/4): Funeral website.
EDITED TO ADD (2/10): Ne… Continue reading David Kahn
GCHQ has released new images of the WWII Colossus code-breaking computer, celebrating the machine’s eightieth anniversary (birthday?).
News article.
Continue reading New Images of Colossus Released
Looks like fun.
Details here.
Continue reading GCHQ Christmas Codebreaking Challenge