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 …

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). [...]

Bluesky thread. Here’s the paper, from 1957. Note reference 3. [...]

Law journal article that looks at the Dual_EC_PRNG backdoor from a US constitutional perspective: Abstract : The National Security Agency (NSA) reportedly paid and pressured technology companies to trick their customers into using vulnerable encryption products. This Article examines whether any of three theories removed the Fourth Amendment’s requirement …

In response to a FOIA request, the NSA released “ Fifty Years of Mathematical Cryptanalysis (1937-1987),” by Glenn F. Stahly, with a lot of redactions. Weirdly, this is the second time the NSA has declassified the document. John Young got a copy in 2019. This one has a few less …

In “ Secrets and Lies ” (2000), I wrote: It is poor civic hygiene to install technologies that could someday facilitate a police state. It’s something a bunch of us were saying at the time, in reference to the vast NSA’s surveillance capabilities. I have been thinking of that …

2006 AT&T whistleblower Mark Klein has died. [...]