loading

What kind of code or cipher is this?

I'm working on a puzzle and can't identify the type of code this is.  I'm not looking for somebody to solve it for me, I just want to research it and learn how to solve it myself.  I can't really do that until I know what I'm dealing with and various Google searches have turned up no information of value.

This is a small portion of the code and I have no additional information or clues:
BT RK RV YC NP GZ YY AA LS HZ NL RR ES IC AN BF RG SS EU VD NF YC SS RH MH MH
MH MH MF HN LS HO GY YV UG IC AS GK BT LS HG AD LS HP CV NT

There are 95 groups of 2 letters each.  I have tried a couple of things which have not given me any result.

I'd really appreciate any kind of information as to what I'm looking at.  Thanks!

pharris35 years ago
If looked at as abbreviations, a lot of them are related to Meteorology.
kattja6 years ago
When faced with a cypher the grouping of the individual letters is often immaterial. The fact that they are in pairs suggest that the maker want you to concentrate on that. Instead I would : Either put all the letter together and try them out in matrixes or in substitution code. Or I would start to count which letters are most common and try that out against the most common languages. It could also be a double-coded message, where you first use some kind of grid code like Caesar's code and afterwards another type of simple code, in order to make it more unbreakable.. Good luck, K
kelseymh kattja6 years ago
You're very right that the groups can be (and often are) meant to be misleading. Consider the uniform five-letter groups in the old one-time pads. In this case, though, the frequencies also suggest that it's not a simple (or even compound) substitution cipher -- "MHMHMHMH" doesn't get you anything sensible in a Latinate language.
kelseymh6 years ago

The digraphs make it look like a Playfair cipher, except that there are too many letters in the combinations (Playfairs typically have just five initial, and five final, letters in each digraph).

The set of four repeats (MH) suggests that these pairings don't represent individual letters (unless the plaintext is Welsh or Hawaiian :-).

I tried both a Google and Wikipedia scan of ciphers, cryptology, etc., but got no inspiration. One-time pads are typically blocked in fives, not twos. Ah. I just tried "two-letter group cipher" on Google, and got this on the first page of hits. Don't know if it's the answer, but it might further your search.