5.4M views · Jan 14, 2013 · 10:58 · 4 HN recommenders · 4 mentions · discussed 2013–2025
Numberphile's Dr James Grime explains the flaw in the Enigma machine, namely that a letter could never be encrypted to itself, and how that helped the Allies break the code. It touches on the Bombe and Alan Turing.
Why Hacker News points people here: HN points to it as a short, clear explanation of why Enigma was breakable and how search-space elimination works.
“Numberphile gives a nice, succinct explanation”HN comment, 2017
“Some people might like this from Numberphile which describes the flaw in the enigma machine”
Describes the flaw that let codebreakers crack Enigma.
Some people might like this from Numberphile which describes the flaw in the enigma machine that British code breakers used to eventually break the code. this video
“Numberphile gives a nice, succinct explanation”
Succinct explanation of Enigma's exploitable flaws.
In this case, a more relevant example from World War II might be the exploitation of flaws in the Enigma machine, namely: 1) the re-use of common phrases in weather reports, and 2) the fact that a letter could not be encoded as itself in the ciphertext, providing a mechanism of contradiction that drastically sped up elimination of possible settings link Numberphile gives a nice, succinct explanation this video
“numberphile has a great video on that one”
Explains search-space elimination like cracking Enigma.
none of it is "brute force", GNFS is a process that rapidly excludes numbers from the search space that cannot be the answer, in principle similar to the way they broke enigma. numberphile has a great video on that one this video Also, taking the OP as a "worse case", afaik: 512bit = $8 so 1024 = 8^2 = $64 2048 = 8^2^2 = $4,096 4096 = 8^2^2 = $16,777,216 noting $8 for 512 seems very expensive to me.
“Also a more proper explanation”
A proper explanation of Enigma's weakness.
There's the entertaining bit in the film The Imitation Game (the breaking of Enigma code by Alan Turing) where they realised that a weakness was the daily weather report always containing the words "weatherreport" and "heil bloody hitler" (with obvious addition!) link or longer version: link Also a more proper explanation: this video
