Friday, November 26, 2010

Notes on Kryptos Part 4

Copy of message I sent to the Kryptos group on Yahoo! for anyone whose working on Kryptos but not in that group.

Given Elonka's notes mentioning that K4 uses a cipher system not known to anyone else I decided to investigate other possible ways of attacking K4. Specifically, I wondered if the BERLIN crib might not be as simple as NYVTT turning letter for letter into BERLIN.

First I assume that this is something that's breakable by hand as was the rest of Kryptos and thus would simply be based on MOD 26 arithmetic of letters and might involve transposition of characters.

So I went to see if there's a word that could be permuted to create some permutation of BERLIN from NYVTT. There is: it is SILENT

NYVTT
ENTSIL
-----
RLINBE

More strikingly this works if you are sliding SILENT from the start of K4, it falls in just the right position to make BERLIN

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
SILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTS
GJVVHHPWRLHETAZPVYTJHJYKNYBTEGYSDWBMOBBWWJKAPOMSOIENXEMLTEJBFNMRLINBEQMYHSHKQDRFENPWAOVYUNSCPOPTJ

Now leading on from this I wonder if the cipher used for K4 consists of permutations of both the key and the ciphertext. Note how BERLIN is permuted within itself and so then I returned to the start of cipher text to see if there's a permutation of SILENT that results in a word (after permutation) starting in position 0. Once again there is:

OBKRUO
ILENTS
------
WMOENG

i.e. the word is WOMEN, assuming that the G is in the word after women. In this case ILENTS is a simple rotate of the word SILENT (just as ENTSIL followed by ENTSIL gives us BERLIN). There are likely other words as well, but this one is strikingly long.

Running through all six possible rotations of SILENT you get:

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
SILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTS
GJVVHHPWRLHETAZPVYTJHJYKNYBTEGYSDWBMOBBWWJKAPOMSOIENXEMLTEJBFNMRLINBEQMYHSHKQDRFENPWAOVYUNSCPOPTJ

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
ILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSI

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
LENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSIL
ZFXKMWISTAMTMWBEANMFJYDZGUDIJVROFLGBHXDLBYDWRDRHHEGCCTFHVTOQYJOGQXGXGFRNAOJZVSKBGCULTKXNZCLYRDUIC

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
ENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILE
SODJCZBBZZCWFFHDQQFOPXTCZDJHZYKXLKWEAGJKRBWFXCHKANMBSWYQBSETRSUFGAZGMEHQTXPYLVDKMBKOMTDMPFEHXCKLV

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
NTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILEN
BUCZFSKHYPFPOLGTTJOUONWVIJIXCRTDKAZXJMIAUUFLWSKDJTLRVPHWAIHMAYTVJTIMLUKJCDOOOOMQLRNHVZCCSYNNWSNEE

OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR
TSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENTSILENT

If you look you'll see various words popping out (in the ILENTS set, second row above, there's WOMEN at the beginning and closer to the end an anagram of WATCH).

Perhaps there's a method to choosing which shift of SILENT to use followed by some sort of transposition.