Secret Agents Hold Code-Breaking Contest

Spudley writes "I just heard on the BBC that the British Government's not-so-secret code breaking organisation, GCHQ, has launched a little Christmas crypto challenge for all you budding secret agents. Should be fun to try it out... even if you're not brave enough to actually send in an entry."

GCHQ

[Gilesx]

I live a mile from GCHQ - it looks like a huge donut, and is apparently mostly built underground. The scarey thing is that I recently read that it's the second most desirable terrorist target after the Whitehouse. Nice!

interesting "puzzle" at most

[tomstdenis]

Modern crypto isn't based on oddly configured puzzles [e.g. once you learn the algo the solution is simple].

While this is a nice puzzle and certainly I couldn't solve it in the 2 mins I was staring at it this has nothing todo with modern crypto. Have an AES breaking contest if you want to promote real research.

Tom

Re:interesting "puzzle" at most

[wronski]

This is not about promoting research. Most people think (with some reason that spying agencias like GCHQ are somewhat creepy. So they promote a nice and cuddly puzzle contest as if to say 'Look, we are just regular guys who like to have some fun and read other countries' diplomatic mail every now and then'.

Reminds me a bit of the CIA Homepage for Kids [cia.gov], but not nearly as weird.

Re:Answer:

[emmetropia]

Ovaltine? Why do they call it ovaltine? Shouldn't they call it roundtine? I await the wrath of the mod's.

Tools...

[perlionex]

Try using/modifying these tools:

frequency analyzer [thepen.com]

caesar cipher cracker [sentex.net]

some other tools also available here [pintday.org]

Re:GCHQ

[10Ghz]

How many uneducated terrorists even know this place exists?

What makes you think that the people who come up with the terrorist-attacks are "uneducated"?

I am not a mama's boy!

[HarveyBirdman]

But I must give this to me mum. She solves the simple daily cryptogram puzzle in the paper in her head. She startes at it for a minute, and, boom, she just has the decrypted version. I always told her she would have made a good spook.

She did work in the aerospace industry before retiring, though. Hmm...

Another good thing about the article was I didn't know Singh had a new book coming out. Cool. I keep "The Code Book" here at work and it's been beaten up through many borrowings by coworkers.

how to solve

[Sogol]

This is actually quite trivial. The key lies in the encrypted mans name BZGZD A'GAANZ. Note the apostrophe. It is reasonable to guess that A==O because many british surnames begin with O-apostrophe.

Apply the substitution and you get BZGZD O'GOONZ. It is reasonable to guess the last name O'TOOLE, which gives us the solution for T, L, and E.

This name is PETER O'TOOLE, and with these letters, the rest of the name is easy to solve.

Edgar Poe - The Gold Bug

[apankrat]

Or better yet read Edgar Poe's The Gold Bug [eserver.org] and follow the recipe :)

Here Legrand, having re-heated the parchment, submitted It my inspection. The following characters were rudely traced, in a red tint, between the death's-head and the goat:

53++!305))6*;4826)4+.)4+);806*;48!8`60))85;]8*:+ *8 !83(88)5*!;

46(;88*96*?;8)*+(;485);5*!2:*+(;4956*2(5*-4)8`8* ; 4069285);)6

!8)4++;1(+9;48081;8:8+1;48!85;4)485!528806*81(+9 ;4 8;(88;4(+?3

4;48)4+;161;:188;+?;

...

"And you really solved it?"

"Readily; I have solved others of an abstruseness ten thousand times greater. Circumstances, and a certain bias of mind, have led me to take interest in such riddles, and it may well be doubted whether human ingenuity can construct an enigma of the kind which human ingenuity may not, by proper application, resolve. In fact, having once established connected and legible characters, I scarcely gave a thought to the mere difficulty of developing their import.

"In the present case --indeed in all cases of secret writing --the first question regards the language of the cipher; for the principles of solution, so far, especially, as the more simple ciphers are concerned, depend on, and are varied by, the genius of the particular idiom. In general, there is no alternative but experiment (directed by probabilities) of every tongue known to him who attempts the solution, until the true one be attained. But, with the cipher now before us, all difficulty is removed by the signature. The pun on the word 'Kidd' is appreciable in no other language than the English. But for this consideration I should have begun my attempts with the Spanish and French, as the tongues in which a secret of this kind would most naturally have been written by a pirate of the Spanish main. As it was, I assumed the cryptograph to be English.

...

Give it a read. Great stuff, especially considering Poe lived in first half of 19th century.