GCHQ Cracks Frank Sidebottom's Codes(bbc.co.uk) |
GCHQ Cracks Frank Sidebottom's Codes(bbc.co.uk) |
And they say the universe doesn't have a sense of irony...
Anybody who's only seen the fictional film representation may find it surprising.
This one was apparently made more difficult by the fact that every other symbol was random. (And apparently using some symbols that did not otherwise appear in the code.)
Though two triangles are used per letter - you can check that with one of the examples which has a message "Why does my nose hurt after concerts?" - 37 characters in total (including spaces), then count the triangles - 74. Hence two inside triangles are used per character.
But certainly highlights how adding noise to any encryption has it's upsides.
That's assuming that the secret is the encryption algorithm itself rather than the key. Modern symmetric encryption does not work that way - the algorithm is public and well known while the key is the actual secret required for encryption/decryption.
I don't see how adding noise in modern encryption can help other than increase the size of the output.
Some modes of operation make use of random noise (IV in CBC, nonce in CTR, etc) because it's a convenient way to get a unique number but it's not for obscurity, it's because it's needed to prevent attacks on these modes.
> But it was impossible to crack them […]
Confirmed uncrackable. He looked at it Jim, what else was he supposed to do??
"GCHQ told Sullivan that Sidebottom "had a small but dedicated following" among its staff."
Couple of people do Sidebottom dialogues as an in-joke to the extent that it begins to annoy co-workers.
"[After random outer triangles explained] 'Right, we've cracked it during a light-hearted training exercise.'"
Took a couple of minutes as a starter in a session.
PS: I use a Playfair style grid to jumble up my pass phrases to try to make them less susceptible to rainbow table attack. Am I wasting my time?
You know you are, you really are.
Is it really that hard to fool some of the worlds top code breakers, simply by including some random digits?
So a code where every {x} symbol is random, and suddenly you've got an uncrackable code? Surely it cant be that simple?
tlhpebcokqodengisxf
And keep in mind that is the code before it's enciphered. Even better, the random characters could be not entirely random but rather weighted to try to bring most characters in the message to a roughly similar frequency. So far as I know the primary tool of code cracking is just plain old frequency analysis. Curious if anybody has any proposals on how this would even be possible to crack.
From there, you'd certainly notice if one side had a lot more symbols than the other side. Trying to analyze both separately is a decent next step, and we are well along to solving this.
A simple substitution cipher is easily broken by frequency analysis - find the most common letter in the ciphertext and it'll probably be E in the plaintext. Nothing so simple would work today, but we often see vulnerabilities in cryptosystems due to pseudorandom number generators with inadequate entropy. It's the same basic principle (exploiting a lack of randomness to identify patterns in the ciphertext), albeit with vastly more mathematical sophistication. The NSA allegedly took advantage of this principle to deliberately weaken cryptosystems by promoting an intentionally weak PRNG.
With AES etc, though, building a system that uses them effectively is the core principle of modern security and crypto.
This step is harder than people think.
I believe allied code cracking in WW2 was helped by one wireless operator habitually ending their transmission "Heil Hitler" or something.
German Enigma operators in WW2 were told always to send a certain number of messages per day to make it harder to perform traffic analysis. One bored operator sent a message composed entirely of "W" repeated 4000 times (or so).
One on-the-ball analyst noticed a message that had no "W"s in it, and deduced what had been sent[0]. That allowed the daily settings to be cracked, and thus all messages for that day.
[0] Enigma has a weakness in that no letter can be encrypted as itself[1].
[1] Enigma is effectively a "one-time-pad" where the pad is a pseudo-random sequence determined by the daily settings.
Nonce is from "then anes", meaning "the one".
The "-n" got smooshed into the latter word, to become "nonce", rather like "an ewt" became "newt".
Then there's a lot of master/slave terminology.
https://www.dailywritingtips.com/nonce-words-for-the-nonce-a...
Also, GP's "Surfari" doesn't sound like a word meant to be used once, but as a word meant to be funny and with high probability of becoming a piece of jargon between a band of friends. My wife & I invent words like these all the time (half of them being born from misspelling or moments of confusions). Are they "nonces" too, even though we keep using them?
Any corpus of one word is, by construction, composed entirely of of hapax legomena. I think the wikipedia page is fairly clear on the subject, honestly. In general, they're a phenomenon which is fairly obvious and uninteresting.
Where it becomes slightly more interesting is when, in some long text, an author uses a word the no one knows, and doesn't bother to explain it, and never uses it again. It becomes particularly interesting when trying to translate important ancient texts... what the devil did this word really mean?