FBI needs help breaking this code

[Rain]

http://www.fbi.gov/news/stories/2011/march/cryptanalysis_032911

 

BBFers are smart. Maybe someone here will be the hero? lol

[Gerben42]

Could be either a prank of bogus words trying to confuse the FBI or Meckwell's secret carding agreements.

[gwnn]

Having grown up in Eastern Europe, it's easy for me to see that these are stolen Windows (or possibly Microsoft Office) serial numbers.

[hrothgar]

I don't think that the FBI is looking for "smart", but rather hoping/praying that someone recognizes the particular code being used.

 

Couple very quick observations:

 

1. Certain blocks of characters crop up very often (for example, look for the string "NCBE")

2. It's hard to tell, but it looks as if the line length are divisible by 4

 

It wouldn't surprise me to discover that the code substitutes blocks of 4 charcters for each letter.

In turn, this means that the message length is extremely short.

 

Historically, these types of codes were often broken using frequency analysis.

I'm not sure whether there is enough raw data available to successfully employee these types of techniques.

[helene_t]

Digits form the same patterns as they do in normal text, i.e. sequences like "651" and "99.84" may be unencrypted. Not sure if the brackets mean anything. For a large part, each line is just in brackets. They could be redundant.

 

Since the notes are hand-written they are likely to have been encrypted manually so the algorithm must be quite simple. But at the same time, since FBI offers no clues as to which algorithm has been used, it must be something that leaves little statistical signature on the cipher text.

 

My guess would be that it is a simple character substitution where the n'th character is shifted k places alphabetically where k is the n'th character in the key, i.e. the key could be as along as the plain text. If the key has some statistical signature (it could be a text written in English) then FBI would have broken it long ago I think. If the key is pure random then it is impossible to break.

[matmat]

heh... the E looks like either a stop symbol or a space.

[Uncle Max]

The "se" at the end of letter groups seems to appear too often to be actual letters or a letter. I'm guessing it's a pointer toward a key to be used to decipher the letters that go before in the group. Same for "te". So he has a couple or a few keys he applies to groups of letters. Similarly, the n appears too often and in odd places in strings to actually be a letter. It's also written unusually. So I'm guessing it's part of the code -- maybe negating or reversing the key from time to time. I saw a comment suggesting pg 1 is a recipe. That would explain all the repetition. Pg 1 also looks a bit like a computer program. I think this will turn out to be a simple but slightly irrational code, which is why the experts are stumped. The keys might be hidden on the "Notes" page to help remind him, though if he's been using them for many years he may have them in his head. First line in third group on Notes pg is interesting, almost symmetrical around the "2", with broken symmetry making "nmnl" "cbrnse" "wsr" and "pte" look like words.