[HN Gopher] Declassified Cold War code-breaking manual on solvin... ___________________________________________________________________ Declassified Cold War code-breaking manual on solving 'impossible' puzzles Author : sandebert Score : 110 points Date : 2021-06-05 08:56 UTC (14 hours ago) (HTM) web link (phys.org) (TXT) w3m dump (phys.org) | zeeshanqureshi wrote: | Good to see [0] Polya's book mentioned (and linked) in the | article. For anyone interested, it provides a pretty good general | outline for problem solving techniques. [1] There's also a | YouTube video of him explaining some of those methods. | | [0] | https://math.hawaii.edu/home/pdf/putnam/PolyaHowToSolveIt.pd... | | [1] https://www.youtube.com/watch?v=h0gbw-Ur_do | azalemeth wrote: | It's worth saying that the book isn't _entirely_ declassified. 18 | out of 84 sections (including quite a few "Further remarks" or | "Final remarks" sections) are completely whited out by the | censor's box. | | Also, the actual PDF is here: | https://www.governmentattic.org/39docs/NSAmilitaryCryptalyti... | ffhhj wrote: | > 6. Fundamental cryptanalytics in the solution of aperiodic | systems. | | That section is white. Is there any information on cyphers that | generate codes indistinguishable from absolute randomness based | on the properties of entropy? | qsort wrote: | The only cypher that satisfies your request is "XOR the | signal with noise, where the noise is a shared secret". | | Generally, you only require a weaker property: that a time- | bounded attacker is unable to assert that the cyphertext is | random with neglegible probability. | thaumasiotes wrote: | https://en.wikipedia.org/wiki/One-time_pad | | Note that for the code to be indistinguishable from absolute | randomness, you need the key to be as long as the text. | westcort wrote: | My grandfather worked with Lambros and shared an amusing booklet | from him called "A short list of even primes," which is a single | digit: 2 (with a long and humorous introduction). It is not | classified (obviously) and I will try to get around to sharing it | on here at some point in the future. | rvba wrote: | Maybe I misunderstand something, but the article text says: | | > in 1992, the US Justice Department claimed releasing the third | book could harm national security by revealing the NSA's "code- | breaking prowess". It was finally released in December last year. | | When we move to the first page of the linked book it says: | | > This text constitutes the third in the series of six basic | texts on the science of cryptanalytics. | | So there is still book 4, 5 an 6? | | (im probably on some list just for asking) | fodmap wrote: | https://en.wikipedia.org/wiki/Military_Cryptanalytics | TedDoesntTalk wrote: | > So there is still book 4, 5 an 6? | | Yes, and they are still classified (for now). | | Part III has been long sought after. Glad to see it's out there | (and that it's release doesn't jeopardize anything) | FredPret wrote: | It's the Cryptonomicon! ___________________________________________________________________ (page generated 2021-06-05 23:00 UTC)