I was on my way to work this afternoon (yes, I know it's a Sunday) when I chanced upon a strange thing lying on the grass verge lining the footpath leading to my office.
It was a little piece of A4-sized cardboard, with what seemed to be some code scribbled on it, and it read:
CCBA DAHIJ EFGABI
BICGHG BACHEFG CBA
HCIBCG FECAB BBCEG
AIBG DE GGJC BEGD
GFHABA JCGEF BCDEF
IIGHCA ECCFG DEJJJ
HICEF ICBCA AAFFG CJ
EGA BCADD BBAI DJJ
( You may find a picture of said object here: http://www.flickr.com/photos/silvr/226065730/ )
The fact that it was scrawled on a piece of cardboard then carelessly discarded beside a busy footpath rather than sealed in a vault on triple-redundant hard disks leads me gently to the assumption that it - if a code - is probably some form of simple monoalphabetic substitution cipher, polyalphabetic at most.
My gut feeling tells me this is breakable, if it's anything at all. I shall give it a go one of these days and let you folks know what happens.
So far:
Alex has pointed out that the chinese words scribbled in blue at the top, "Xian Xin Liang Ku" could well be a taunt. It's a take on a common Chinese phrase "Yong Xin Liang Ku" which loosely means that someone has given a lot of thought or put a lot of effort into something. "Xian Xin" here means "an idle heart / mind".
Whamdangler from TotalFark has pointed out that the second word is "JIHAD" spelt backwards. Coincidence?
Also, he sez "2210 30789 456018 182676 1027456 210 728126 54201 11246 0816 34 6692 1463 657010 92645 12345 886720 42256 34999 78245 82120 00556 29 460 12033 1108 399
That's the code in numbers, if anyone cares. Note, it's 0-9 instead of 1-10″
I_C_Weener from TotalFark figures, "My guess is its a substitution cipher, but after each substitution, you rotate to the next letter.
So, the first time, J = A, and the second time you see J, it = B. That is how you have words with 2 or 3 of the same letter.
But, if I deciphered it for you, where would be the fun.
Here is a hint: The first line is 'For a good time call....'"
Micheal Slater has kindly recommended a frequency-analysis tool. I'll give it a shot and see if anything turns up.
SharQ from E2 says, "It strikes me that only the letters A-J are used. At first I thought it might be some sort of musical notation. I have my doubt that this is a code. It looks like someone has been systematically trying something or other, and has just written down what they ahve been trying"
kthejoker from E2 says, "Clearly the letters represent the digits 0 through 9. The question you have to ask yourself is 'what kind of system could I create that I could make letters / words using the digits 0 through 9?'" (Hmm. Mathematical equations? I have tried the frequency analyzer. Nothing significant.) | 
