# What is the code in the following sequence of numbers?

6-1, 9-3|4-1,6-3 2-1,5-3|
4-3.6-2|2-1,6-1,3-2,7-3,4-3,2-3,2-1|
6-1,3-2,2-1,6-2,8-1|6-1,9-3|3-1,6-3,6-3,6-1|

• Is this your own puzzle? Jul 8 '18 at 12:32
– m4n0
Jul 9 '18 at 1:42

The riddle, to which I don't know the answer, is:

My goal in America means my doom.

How did I find it?

The cipher text consists of pairs of digits joined by hyphens. The peris are separated by either commas or vertical bars. (I assume that the omission of the comma and the period instead of a comma are transcription errors.)

This layout suggests a substitution cipher, where each number pair represents a letter. Commas separate letters of a word and vertical bars separate words.

Also note that the second number is one of 1, 2 or 3 and the first number ranges from 2 to 9. So these numbers could represent columns and rows on a keyboard. (That's not true, but let's use it a a working hypothesis, as Sherlock Holmes would have said.) If we take row 1 to be the bottom row, this substitution yields:

NO VYXT RH XNDURWX NDXHQ NO CYYN

That's not a useful sentence. Also, our hypothesis has fallen flat, because 8-1 would have been a comma. I've used Q, a letter that hasn't been used yet, instead. (The 8-1 is at the end of a word and could well be a comma, though. But let's not consider that right now.)

While that's not a valid sentence, we now have a valid cryptogram, which we can feed into an automatic solver such as Quipqiup. You could also try to solve the cryptogram by means of frequency analysis and guessing, which is arguably more fun. You don't even have to use the transformed sentence for that; you could work on the number pairs directly.

Anyway, Quipqiup spits out several possible solutions. There seem to be a lot of possibilities for the second and last words, which have letters that aren't used anywhere else, but it seems clear that the sentence is:

MY ..A. IN AMERICA MEANS MY ....

where each . is a letter that hasn't been used yet. Without further information, we can't know what they are, but fortunately, we do have further information. Let's plot the known letters in a grid:

            1 2 3 4 5 6 7 8 9
1     A       M   S
2       E     N
3     C   I     R   Y

See a pattern here? Sure you do:

            1 2 3 4 5 6 7 8 9
1     A D G J M P S V
2     B E H K N Q T W
3     C F I L O R U Y*

(* perhaps the last slot means XYZ here, otherwise the enumeration doesn't quite fit and there isn't any way to represent Z. Anyway, that's not important for the original code.)

Now use this handy decoding table to get the riddle above.