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Chaocipher Exhibit 5 Solution - Now published in Cryptologia
Topic Started: Jan 22 2014, 12:59 AM (749 Views)
jcalof
Just registered
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This morning, Cryptologia published the article I co-wrote with Moshe Rubin and Jeff Hill titled "Chaocipher Exhibit 5: History, Analysis, and Solution of Cryptologia's 1990 Challenge". Here's a link to the online version:

http://www.tandfonline.com/toc/ucry20/current

The hard-copy journal of Volume 38, Issue 1, 2014 should be available in a few weeks.

Due to copyright restrictions, we're not able to forward soft-copies of the article. It's possible we can upload a photo of the actual Exhibit 5 Solution Document (as it was found in the National Cryptologic Museum files), along with an earlier, altogether different version of Exhibit 5 (never published), to the Chaocipher Clearing House website, in the near future. I'll post again if/when that transpires.

As Moshe noted in an earlier thread, we found that the published Exhibit 5 in the 1990 Cryptologia had ciphertext transcription errors in two of the three messages (when compared to the encipherment schema set forth in the Solution Document). The article goes into depth on this as well as other aspects of Exhibit 5's history. As a bonus, the "Unpublished Exhibit 5" draft has now been re-christened "Exhibit 6" by Moshe, Jeff, and me. With Exhibits 1-4 now also in the "solved" column, it presents the last and, possibly, most challenging Chaocipher message yet (as there's no plaintext, known encipherment schema, or knowledge of its source to assist).



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jcalof
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Thank you, everyone, for your patience. With it now being 2 months since the Cryptologia article got published, I have now uploaded an abbreviated article to The Chaocipher Clearing House with the Exhibit 5 solution and a short overview. It may be read in Progress Report #23: http://www.mountainvistasoft.com/chaocipher/chaocipher-023.htm

Thanks, as always, to Moshe Rubin for hosting the Clearing House and his assistance (along with Jeff Hill) in verifying the solution.

Next week, I will upload an earlier draft (found at the National Cryptologic Museum) prepared by Kruh & Deavours that contains an entirely different encipherment schema. We have dubbed this "Exhibit 6" and for any Chaocipher researcher this remains the final Exhibit to solve... and, as you will see, likely the most challenging.

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mosher
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I, for one, am indebted to Jeff for traveling across the US, from California to Maryland, for the express purpose of examining and photographing the Chaocipher archives at the National Cryptologic Museum. Without his tenacity we would still be in the dark about Kruh & Deavours's 1990 challenge messages.

For anyone who tries to generate the starting alphabets from K&D's work sheet, here are the steps used to generate them together with the generated starting alphabets, as produced by my Perl script. Note that the alphabet used to find the plaintext letter changes according to the "PT disk pattern".

Generating the starting alphabets
 

Session options
===============
Left starting alphabet:  ABCDEFGHIJKLMNOPQRSTUVWXYZ
Right starting alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Left zenith: A
Right zenith: A
PT disk pattern: RLRRLLLRRRLLLLRRRRRLLLLLLRRRRRR
Input text:      IMAGINATIONINSPIRATIONINTUITION
Output file:
Command line input:
Mode: encipher


Input text has 31 characters

( 0) leftAlphabet:  ABCDEFGHIJKLMNOPQRSTUVWXYZ
( 0) rightAlphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ
( 0) Plain disk is the RIGHT disk

( 0) pt(I) = ct(I)

( 1) leftAlphabet:  IKLMNOPQRSTUVJWXYZABCDEFGH
( 1) rightAlphabet: JKMNOPQRSTUVWLXYZABCDEFGHI
( 1) Plain disk is the LEFT disk

( 1) pt(M) = ct(N)

( 2) leftAlphabet:  MOPQRSTUVJWXYNZABCDEFGHIKL
( 2) rightAlphabet: OPRSTUVWLXYZAQBCDEFGHIJKMN
( 2) Plain disk is the RIGHT disk

( 2) pt(A) = ct(Y)

( 3) leftAlphabet:  YZABCDEFGHIKLNMOPQRSTUVJWX
( 3) rightAlphabet: QBDEFGHIJKMNOCPRSTUVWLXYZA
( 3) Plain disk is the RIGHT disk

( 3) pt(G) = ct(D)

( 4) leftAlphabet:  DFGHIKLNMOPQRESTUVJWXYZABC
( 4) rightAlphabet: HIKMNOCPRSTUVJWLXYZAQBDEFG
( 4) Plain disk is the LEFT disk

( 4) pt(I) = ct(N)

( 5) leftAlphabet:  ILNMOPQRESTUVKJWXYZABCDFGH
( 5) rightAlphabet: OCRSTUVJWLXYZPAQBDEFGHIKMN
( 5) Plain disk is the LEFT disk

( 5) pt(N) = ct(R)

( 6) leftAlphabet:  NOPQRESTUVKJWMXYZABCDFGHIL
( 6) rightAlphabet: STVJWLXYZPAQBUDEFGHIKMNOCR
( 6) Plain disk is the LEFT disk

( 6) pt(A) = ct(G)

( 7) leftAlphabet:  ACDFGHILNOPQRBESTUVKJWMXYZ
( 7) rightAlphabet: HIMNOCRSTVJWLKXYZPAQBUDEFG
( 7) Plain disk is the RIGHT disk

( 7) pt(T) = ct(N)

( 8) leftAlphabet:  NPQRBESTUVKJWOMXYZACDFGHIL
( 8) rightAlphabet: VJLKXYZPAQBUDWEFGHIMNOCRST
( 8) Plain disk is the RIGHT disk

( 8) pt(I) = ct(A)

( 9) leftAlphabet:  ADFGHILNPQRBECSTUVKJWOMXYZ
( 9) rightAlphabet: MNCRSTVJLKXYZOPAQBUDWEFGHI
( 9) Plain disk is the RIGHT disk

( 9) pt(O) = ct(C)

( 10) leftAlphabet:  CTUVKJWOMXYZASDFGHILNPQRBE
( 10) rightAlphabet: PABUDWEFGHIMNQCRSTVJLKXYZO
( 10) Plain disk is the LEFT disk

( 10) pt(N) = ct(L)

( 11) leftAlphabet:  NQRBECTUVKJWOPMXYZASDFGHIL
( 11) rightAlphabet: KXZOPABUDWEFGYHIMNQCRSTVJL
( 11) Plain disk is the LEFT disk

( 11) pt(I) = ct(J)

( 12) leftAlphabet:  INQRBECTUVKJWLOPMXYZASDFGH
( 12) rightAlphabet: LKZOPABUDWEFGXYHIMNQCRSTVJ
( 12) Plain disk is the LEFT disk

( 12) pt(N) = ct(K)

( 13) leftAlphabet:  NRBECTUVKJWLOQPMXYZASDFGHI
( 13) rightAlphabet: ZOABUDWEFGXYHPIMNQCRSTVJLK
( 13) Plain disk is the LEFT disk

( 13) pt(S) = ct(S)

( 14) leftAlphabet:  SFGHINRBECTUVDKJWLOQPMXYZA
( 14) rightAlphabet: TVLKZOABUDWEFJGXYHPIMNQCRS
( 14) Plain disk is the RIGHT disk

( 14) pt(P) = ct(O)

( 15) leftAlphabet:  OPMXYZASFGHINQRBECTUVDKJWL
( 15) rightAlphabet: IMQCRSTVLKZOANBUDWEFJGXYHP
( 15) Plain disk is the RIGHT disk

( 15) pt(I) = ct(O)

( 16) leftAlphabet:  OMXYZASFGHINQPRBECTUVDKJWL
( 16) rightAlphabet: MQRSTVLKZOANBCUDWEFJGXYHPI
( 16) Plain disk is the RIGHT disk

( 16) pt(R) = ct(X)

( 17) leftAlphabet:  XZASFGHINQPRBYECTUVDKJWLOM
( 17) rightAlphabet: STLKZOANBCUDWVEFJGXYHPIMQR
( 17) Plain disk is the RIGHT disk

( 17) pt(A) = ct(H)

( 18) leftAlphabet:  HNQPRBYECTUVDIKJWLOMXZASFG
( 18) rightAlphabet: NBUDWVEFJGXYHCPIMQRSTLKZOA
( 18) Plain disk is the RIGHT disk

( 18) pt(T) = ct(X)

( 19) leftAlphabet:  XASFGHNQPRBYEZCTUVDIKJWLOM
( 19) rightAlphabet: LKOANBUDWVEFJZGXYHCPIMQRST
( 19) Plain disk is the LEFT disk

( 19) pt(I) = ct(P)

( 20) leftAlphabet:  IJWLOMXASFGHNKQPRBYEZCTUVD
( 20) rightAlphabet: IMRSTLKOANBUDQWVEFJZGXYHCP
( 20) Plain disk is the LEFT disk

( 20) pt(O) = ct(T)

( 21) leftAlphabet:  OXASFGHNKQPRBMYEZCTUVDIJWL
( 21) rightAlphabet: LKANBUDQWVEFJOZGXYHCPIMRST
( 21) Plain disk is the LEFT disk

( 21) pt(N) = ct(Q)

( 22) leftAlphabet:  NQPRBMYEZCTUVKDIJWLOXASFGH
( 22) rightAlphabet: WVFJOZGXYHCPIEMRSTLKANBUDQ
( 22) Plain disk is the LEFT disk

( 22) pt(I) = ct(R)

( 23) leftAlphabet:  IWLOXASFGHNQPJRBMYEZCTUVKD
( 23) rightAlphabet: STKANBUDQWVFJLOZGXYHCPIEMR
( 23) Plain disk is the LEFT disk

( 23) pt(N) = ct(V)

( 24) leftAlphabet:  NPJRBMYEZCTUVQKDIWLOXASFGH
( 24) rightAlphabet: FJOZGXYHCPIEMLRSTKANBUDQWV
( 24) Plain disk is the LEFT disk

( 24) pt(T) = ct(I)

( 25) leftAlphabet:  TVQKDIWLOXASFUGHNPJRBMYEZC
( 25) rightAlphabet: EMRSTKANBUDQWLVFJOZGXYHCPI
( 25) Plain disk is the RIGHT disk

( 25) pt(U) = ct(X)

( 26) leftAlphabet:  XSFUGHNPJRBMYAEZCTVQKDIWLO
( 26) rightAlphabet: DQLVFJOZGXYHCWPIEMRSTKANBU
( 26) Plain disk is the RIGHT disk

( 26) pt(I) = ct(Z)

( 27) leftAlphabet:  ZTVQKDIWLOXSFCUGHNPJRBMYAE
( 27) rightAlphabet: EMSTKANBUDQLVRFJOZGXYHCWPI
( 27) Plain disk is the RIGHT disk

( 27) pt(T) = ct(Q)

( 28) leftAlphabet:  QDIWLOXSFCUGHKNPJRBMYAEZTV
( 28) rightAlphabet: KABUDQLVRFJOZNGXYHCWPIEMST
( 28) Plain disk is the RIGHT disk

( 28) pt(I) = ct(A)

( 29) leftAlphabet:  AZTVQDIWLOXSFECUGHKNPJRBMY
( 29) rightAlphabet: EMTKABUDQLVRFSJOZNGXYHCWPI
( 29) Plain disk is the RIGHT disk

( 29) pt(O) = ct(U)

( 30) leftAlphabet:  UHKNPJRBMYAZTGVQDIWLOXSFEC
( 30) rightAlphabet: ZNXYHCWPIEMTKGABUDQLVRFSJO
( 30) Plain disk is the RIGHT disk

( 30) pt(N) = ct(H)

( 31) leftAlphabet:  HNPJRBMYAZTGVKQDIWLOXSFECU
( 31) rightAlphabet: XYCWPIEMTKGABHUDQLVRFSJOZN


INYDNRGNACLJKSOOXHXPTQRVIXZQAUH
Finished!


The final iteration shows the starting alphabets:

Starting alphabets
 
Left Alphabet:  HNPJRBMYAZTGVKQDIWLOXSFECU
Right Alphabet: XYCWPIEMTKGABHUDQLVRFSJOZN
Edited by mosher, Mar 23 2014, 07:56 AM.
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