Newest Code Breaker Contest (By Nod2003)

Is this a polyalphabetic substitution cipher?

Balloons are really cool. So are coins!

Method of decryption:

1. Nod told us early on that there were 7 words, the shortest was two letters and "cones aren't that important". I took that to mean the cones in your eyes (that detect color) weren't as important as the rods (that detect grayscale - sort of). But the color coding did highlight one thing: The lines with the single color coded character added all had an odd number of triplets. Nod was making the number of characters in all lines divisible by two on purpose.

2. The hints about pairs made it obvious that a pair of letters would decode to a single letter when you consider there were a total of 48 pairs and only 31 letters in the answer. After learning that line 1 contained 8 characters and the shortest word was two characters and there was on word per line, there had to be a letter or combination that could be eliminated. The letter T appeared in 17 pairs and conveniently made line one 8 pairs and line 5 two pairs.

3. I converted the pairs into single characters to make decoding easier. I quickly observed that line 2 and line 6 were identical! Line 5 was only 2 characters, so I was trying to make the three character words "and" or "the" or "are" or "our", but nothing worked. Then I started to look at polyalphabetic substitution with a key length of 3 since there was a 15 character spread between the identical words on lines 2 and 6. But then Nod indicated it was a simple substitution and provided a fixed letter. That not only nailed down line 5 (what other two letter word starts with S?) but gave a BIG clue to lines 2 and 6. The word "are" made the most sense so I started there. That left line 3 as REA*** which had to be REALLY, but that made line 4 *OLL. I kept going anyway and immediately saw that line 7 was COINS. That left line one as *ALLOLNS. Then I realized that PS could be "L" or "O" and it fell into place.

First, put all code into pairs. Delete all pairs with the letter T. Then replace:

PA = B
PP = A
GK = L
PS = L or O (it's L, then O, then L, then O)
GS = O
GR = N
BA = S
BP = R
PE = E
PG = Y
PC = C
GP = I

Therefore:

PA PP GK PS GS PS GR BA
PP BP PE
BP PE PP GK PS PG
PC GS PS GK
BA GS
PP BP PE
PC GS GP GR BA

becomes:

BALLOONS
ARE
REALLY
COOL
SO
ARE
COINS

This time, please just give me until Wednsday and then Ill post MY contest. Ok?

Yay, lars got it.

My encoding method was as follows:

I based it on a base 9 numbering system, 1-9. 11 was the minimum and corresponded to the letter G. Since there are only 26 letters, I used the 27th letter as the second of any double letters, for words like cool, really, etc. I then disguised the numbers using my favorite football team as a key. GBPACKERS. To make things a bit more tricky, I then added the letter T and any pair with a T in it was a blank. I then did as lars described with the colors.

nod2003 - Very Clever!
larsdog - What can I say? True Genius!

Although I can never figure these out, they are truly fun to follow.

Thanks guys

I agree with jg86. I chased down a LOT of blind alleys on this one, but the prize fits in a hole in my Type Set collection. Looking forward to see what you have tzar!