Dennis Shasha/Codes, Puzzles, and Conspiracy/3/Humpty Dumpty at the Irish Cliffs

Code

 * Jkwr K wbj N:


 * Ox on kwrhf Nwxzrjwf iarbobt wbj O iotmy haoy el xeil yb klipfls
 * ynm jmzzmt zc zon wddm pevro hvoonov. Po avo ef edv paj be
 * Svolafn. Haryovqfego rct ifd tshye hgy uedm. V'p ihe ugyr stn,
 * sdksyf fufg vu sgtu hwzy uvnzyzlm haivc h yxmdj omnqwdzijamn
 * xajy Wnojuwn Emvkmdn, nyoxe nc Xu Pjabon. Dxezkeb az jqpac
 * mbmn vqp mha sqyerj, tpn E zqptn en.


 * Ca daayd dpdgeseqpdxv cnhhw. "Odc Uzghhf sh Asedk," fe
 * hqzh ltxxivn gji hsxfj hkti nehtkwoh, "uji Afmnnl yn Gykjq. Ezy
 * kngg gntj wlki, Kcca, O wi nzrk."


 * O wi bax. Dzx pahhal ik xa Orkhwbj. If bkvx hkxxkr lohh dk
 * ob xml Vxjlo jaolaj pc Dbsv. P nygm kylm y ozgra ds hrqrarew ra
 * opofoiov S'm sf bqp bwpb. Kfe qtmm utgo crq ifxcdgx dg jq c
 * tdxchzq jfd tuhiqxq ncpl hcoqp Chhq G'Ighhqnn. Ngicn wqgwnq
 * dsvib uts'v kzegn twfu fqq vub hgre kz Ylmg xhklu mgboyldx yl
 * Yburglt. Njh xwv zy hm lkiyihmuzme evmvhslezyi. Ivss xwd rml idw
 * jdranf jm banv rmld omlzan Aziio M'Omnnwtt. Zyx ybuu gbrx snm
 * kzy poly.


 * U

Solution

 * Initial Observations

The message is a letter.

It is assumed that it is written in a substitution cipher such that the punctuation and word structure are unchanged.

Based on the first coded letter, the first line is clearly

Jkwr K wbj N: Dear E and S:

where E and S stand for Evangeline and Scarlet.

It is also assumed that the U at the end is J.

It can be seen that there are several occurrences of a single-letter word consisting of one capital letter.

There is only one such in the English language, that is: I.

Initial observation suggests that the key is the same as that for the first coded letter.

This assumption is based directly on the fact that wbj means and in both letters.

Recall:

S psll feb I will not

ho ahlo be dro bqsr geno axasf. be able to use this code again.

Bqo ofgensfx et bqo morraxo S loaio fozb bsmo psll vebabo The encoding of the message I leave next time will rotate

efgo oagq bsmo bqo morraxo gefbasfr bqo lobbov ... poll, jed psll once each time the message contains the letter ... well, you will

tsxdvo sb edb. figure it out.

Recall the key for the initial ciphertext:


 * $\begin {array} {c|c} \text {Plaintext} & \texttt A & \texttt B & \texttt C & \texttt D & \texttt E & \texttt F & \texttt G & \texttt H & \texttt I & \texttt J & \texttt K & \texttt L & \texttt M & \texttt N & \texttt O & \texttt P & \texttt Q & \texttt R & \texttt S & \texttt T & \texttt U & \texttt V & \texttt W & \texttt X & \texttt Y & \texttt Z \\ \hline \text {Ciphertext} & \texttt W & \texttt D & \texttt C & \texttt J & \texttt K & \texttt P & \texttt T & \texttt M & \texttt O & \texttt G & \texttt U & \texttt H & \texttt I & \texttt B & \texttt A & \texttt Q & \texttt S & \texttt R & \texttt N & \texttt X & \texttt Z & \texttt E & \texttt L & \texttt V & \texttt F & \texttt Y \end {array}$

Let us translate the letter, and see what makes sense.

We go at least as far as the occurrences of O in the third paragraph.

Jkwr K wbj N: Dear E and S:

Ox on kwrhf Nwxzrjwf iarbobt wbj O iotmy haoy el xeil yb klipfls It is early Saturday morning and I migh loi   w t m   n ewmfyw

ynm jmzzmt zc zon wddm pevro hvoonov. Po avo ef edv paj be sh dhuuhg uc uis abbh f vri lviisiv. Fi ovi    bv fod n

Svolafn. Haryovqfego rct ifd tshye hgy uedm. V'p ihe ugyr stn, viwoys. Lor iv y i rcg myb g l   l     bh. X'f ml    r  gs,

sdksyf fufg vu sgtu hwzy uvnzyzlm haivc h yxmdj omnqwdzijamn be y y y  x    g  lau   xsu uwh lomxc l  th d ihs abumdohs

xajy Wnojuwn Emvkmdn, nyoxe nc Xu Pjabon. Dxezkeb az jqpac tod Asid as  hxehbs, s it  sc T  Fdonis. Bt ue n o d foc

mbmn vqp mha sqyerj, tpn E zqptn en. hnhs x f lo     rd, gfs   u fgs  s.

Ca daayd dpdgeseqpdxv cnhhw. "Odc Uzghhf sh Asedk," fe Co boo b bfb    fbtx  slla. "Ibc u lly  l O  be," y

hqzh ltxxivn gji hsxfj hkti nehtkwoh, "uji Afmnnl yn Gykjq. Ezy l ul wgttmxs dm l tyd legm s lgeail, " dm Oyhssw  s   eda. u

kngg gntj wlki, Kcca, O wi nzrk." es   sgd awem, Ecco, I am sure."

O wi bax. Dzx pahhal ik xa Orkhwbj. If bkvx hkxxkr lohh dk I am not. But follow me to Ireland. My next letter will be

ob xml Vxjlo jaolaj pc Dbsv. P nygm kylm y ozgra ds hrqrarew ra in thw Xtdwi doiwod fc Bn x.

We have enough of this translated to see that the letter triggering the rotation is h.

Here is the code, in all $26$ variants:


 * $\begin{array}{c|cccccccccccccccccccccccccc}

& \texttt A & \texttt B & \texttt C & \texttt D & \texttt E & \texttt F & \texttt G & \texttt H & \texttt I & \texttt J & \texttt K & \texttt L & \texttt M & \texttt N & \texttt O & \texttt P & \texttt Q & \texttt R & \texttt S & \texttt T & \texttt U & \texttt V & \texttt W & \texttt X & \texttt Y & \texttt Z \\ \hline 1 & \texttt W & \texttt D & \texttt C & \texttt J & \texttt K & \texttt P & \texttt T & \texttt M & \texttt O & \texttt G & \texttt U & \texttt H & \texttt I & \texttt B & \texttt A & \texttt Q & \texttt S & \texttt R & \texttt N & \texttt X & \texttt Z & \texttt E & \texttt L & \texttt V & \texttt F & \texttt Y \\ 2 & \texttt X & \texttt E & \texttt D & \texttt K & \texttt L & \texttt Q & \texttt U & \texttt N & \texttt P & \texttt H & \texttt V & \texttt I & \texttt J & \texttt C & \texttt B & \texttt R & \texttt T & \texttt S & \texttt O & \texttt Y & \texttt A & \texttt F & \texttt M & \texttt W & \texttt G & \texttt Z \\ 3 & \texttt Y & \texttt F & \texttt E & \texttt L & \texttt M & \texttt R & \texttt V & \texttt O & \texttt Q & \texttt I & \texttt W & \texttt J & \texttt K & \texttt D & \texttt C & \texttt S & \texttt U & \texttt T & \texttt P & \texttt Z & \texttt B & \texttt G & \texttt N & \texttt X & \texttt H & \texttt A \\ 4 & \texttt Z & \texttt G & \texttt F & \texttt M & \texttt N & \texttt S & \texttt W & \texttt P & \texttt R & \texttt J & \texttt X & \texttt K & \texttt L & \texttt E & \texttt D & \texttt T & \texttt V & \texttt U & \texttt Q & \texttt A & \texttt C & \texttt H & \texttt O & \texttt Y & \texttt I & \texttt B \\ 5 & \texttt A & \texttt H & \texttt G & \texttt N & \texttt O & \texttt T & \texttt X & \texttt Q & \texttt S & \texttt K & \texttt Y & \texttt L & \texttt M & \texttt F & \texttt E & \texttt U & \texttt W & \texttt V & \texttt R & \texttt B & \texttt D & \texttt I & \texttt P & \texttt Z & \texttt J & \texttt C \\ 6 & \texttt B & \texttt I & \texttt H & \texttt O & \texttt P & \texttt U & \texttt Y & \texttt R & \texttt T & \texttt L & \texttt Z & \texttt M & \texttt N & \texttt G & \texttt F & \texttt V & \texttt X & \texttt W & \texttt S & \texttt C & \texttt E & \texttt J & \texttt Q & \texttt A & \texttt K & \texttt D \\ 7 & \texttt C & \texttt J & \texttt I & \texttt P & \texttt Q & \texttt V & \texttt Z & \texttt S & \texttt U & \texttt M & \texttt A & \texttt N & \texttt O & \texttt H & \texttt G & \texttt W & \texttt Y & \texttt X & \texttt T & \texttt D & \texttt F & \texttt K & \texttt R & \texttt B & \texttt L & \texttt E \\ 8 & \texttt D & \texttt K & \texttt J & \texttt Q & \texttt R & \texttt W & \texttt A & \texttt T & \texttt V & \texttt N & \texttt B & \texttt O & \texttt P & \texttt I & \texttt H & \texttt X & \texttt Z & \texttt Y & \texttt U & \texttt E & \texttt G & \texttt L & \texttt S & \texttt C & \texttt M & \texttt F \\ 9 & \texttt E & \texttt L & \texttt K & \texttt R & \texttt S & \texttt X & \texttt B & \texttt U & \texttt W & \texttt O & \texttt C & \texttt P & \texttt Q & \texttt J & \texttt I & \texttt Y & \texttt A & \texttt Z & \texttt V & \texttt F & \texttt H & \texttt M & \texttt T & \texttt D & \texttt N & \texttt G \\ 10 & \texttt F & \texttt M & \texttt L & \texttt S & \texttt T & \texttt Y & \texttt C & \texttt V & \texttt X & \texttt P & \texttt D & \texttt Q & \texttt R & \texttt K & \texttt J & \texttt Z & \texttt B & \texttt A & \texttt W & \texttt G & \texttt I & \texttt N & \texttt U & \texttt E & \texttt O & \texttt H \\ 11 & \texttt G & \texttt N & \texttt M & \texttt T & \texttt U & \texttt Z & \texttt D & \texttt W & \texttt Y & \texttt Q & \texttt E & \texttt R & \texttt S & \texttt L & \texttt K & \texttt A & \texttt C & \texttt B & \texttt X & \texttt H & \texttt J & \texttt O & \texttt V & \texttt F & \texttt P & \texttt I \\ 12 & \texttt H & \texttt O & \texttt N & \texttt U & \texttt V & \texttt A & \texttt E & \texttt X & \texttt Z & \texttt R & \texttt F & \texttt S & \texttt T & \texttt M & \texttt L & \texttt B & \texttt D & \texttt C & \texttt Y & \texttt I & \texttt K & \texttt P & \texttt W & \texttt G & \texttt Q & \texttt J \\ 13 & \texttt I & \texttt P & \texttt O & \texttt V & \texttt W & \texttt B & \texttt F & \texttt Y & \texttt A & \texttt S & \texttt G & \texttt T & \texttt U & \texttt N & \texttt M & \texttt C & \texttt E & \texttt D & \texttt Z & \texttt J & \texttt L & \texttt Q & \texttt X & \texttt H & \texttt R & \texttt K \\ \end{array}$
 * $\begin{array}{c|cccccccccccccccccccccccccc}

14 & \texttt J & \texttt Q & \texttt P & \texttt W & \texttt X & \texttt C & \texttt G & \texttt Z & \texttt B & \texttt T & \texttt H & \texttt U & \texttt V & \texttt O & \texttt N & \texttt D & \texttt F & \texttt E & \texttt A & \texttt K & \texttt M & \texttt R & \texttt Y & \texttt I & \texttt S & \texttt L \\ 15 & \texttt K & \texttt R & \texttt Q & \texttt X & \texttt Y & \texttt D & \texttt H & \texttt A & \texttt C & \texttt U & \texttt I & \texttt V & \texttt W & \texttt P & \texttt O & \texttt E & \texttt G & \texttt F & \texttt B & \texttt L & \texttt N & \texttt S & \texttt Z & \texttt J & \texttt T & \texttt M \\ 16 & \texttt L & \texttt S & \texttt R & \texttt Y & \texttt Z & \texttt E & \texttt I & \texttt B & \texttt D & \texttt V & \texttt J & \texttt W & \texttt X & \texttt Q & \texttt P & \texttt F & \texttt H & \texttt G & \texttt C & \texttt M & \texttt O & \texttt T & \texttt A & \texttt K & \texttt U & \texttt N \\ 17 & \texttt M & \texttt T & \texttt S & \texttt Z & \texttt A & \texttt F & \texttt J & \texttt C & \texttt E & \texttt W & \texttt K & \texttt X & \texttt Y & \texttt R & \texttt Q & \texttt G & \texttt I & \texttt H & \texttt D & \texttt N & \texttt P & \texttt U & \texttt B & \texttt L & \texttt V & \texttt O \\ 18 & \texttt N & \texttt U & \texttt T & \texttt A & \texttt B & \texttt G & \texttt K & \texttt D & \texttt F & \texttt X & \texttt L & \texttt Y & \texttt Z & \texttt S & \texttt R & \texttt H & \texttt J & \texttt I & \texttt E & \texttt O & \texttt Q & \texttt V & \texttt C & \texttt M & \texttt W & \texttt P \\ 19 & \texttt O & \texttt V & \texttt U & \texttt B & \texttt C & \texttt H & \texttt L & \texttt E & \texttt G & \texttt Y & \texttt M & \texttt Z & \texttt A & \texttt T & \texttt S & \texttt I & \texttt K & \texttt J & \texttt F & \texttt P & \texttt R & \texttt W & \texttt D & \texttt N & \texttt X & \texttt Q \\ 20 & \texttt P & \texttt W & \texttt V & \texttt C & \texttt D & \texttt I & \texttt M & \texttt F & \texttt H & \texttt Z & \texttt N & \texttt A & \texttt B & \texttt U & \texttt T & \texttt J & \texttt L & \texttt K & \texttt G & \texttt Q & \texttt S & \texttt X & \texttt E & \texttt O & \texttt Y & \texttt R \\ 21 & \texttt Q & \texttt X & \texttt W & \texttt D & \texttt E & \texttt J & \texttt N & \texttt G & \texttt I & \texttt A & \texttt O & \texttt B & \texttt C & \texttt V & \texttt U & \texttt K & \texttt M & \texttt L & \texttt H & \texttt R & \texttt T & \texttt Y & \texttt F & \texttt P & \texttt Z & \texttt S \\ 22 & \texttt R & \texttt Y & \texttt X & \texttt E & \texttt F & \texttt K & \texttt O & \texttt H & \texttt J & \texttt B & \texttt P & \texttt C & \texttt D & \texttt W & \texttt V & \texttt L & \texttt N & \texttt M & \texttt I & \texttt S & \texttt U & \texttt Z & \texttt G & \texttt Q & \texttt A & \texttt T \\ 23 & \texttt S & \texttt Z & \texttt Y & \texttt F & \texttt G & \texttt L & \texttt P & \texttt I & \texttt K & \texttt C & \texttt Q & \texttt D & \texttt E & \texttt X & \texttt W & \texttt M & \texttt O & \texttt N & \texttt J & \texttt T & \texttt V & \texttt A & \texttt H & \texttt R & \texttt B & \texttt U \\ 24 & \texttt T & \texttt A & \texttt Z & \texttt G & \texttt H & \texttt M & \texttt Q & \texttt J & \texttt L & \texttt D & \texttt R & \texttt E & \texttt F & \texttt Y & \texttt X & \texttt N & \texttt P & \texttt O & \texttt K & \texttt U & \texttt W & \texttt B & \texttt I & \texttt S & \texttt C & \texttt V \\ 25 & \texttt U & \texttt B & \texttt A & \texttt H & \texttt I & \texttt N & \texttt R & \texttt K & \texttt M & \texttt E & \texttt S & \texttt F & \texttt G & \texttt Z & \texttt Y & \texttt O & \texttt Q & \texttt P & \texttt L & \texttt V & \texttt X & \texttt C & \texttt J & \texttt T & \texttt D & \texttt W \\ 26 & \texttt V & \texttt C & \texttt B & \texttt I & \texttt J & \texttt O & \texttt S & \texttt L & \texttt N & \texttt F & \texttt T & \texttt G & \texttt H & \texttt A & \texttt Z & \texttt P & \texttt R & \texttt Q & \texttt M & \texttt W & \texttt Y & \texttt D & \texttt K & \texttt U & \texttt E & \texttt X \end{array}$

So we continue.

Every time we encounter the encoding for the letter h, we change key.

Jkwr K wbj N: Dear E and S:

Ox on kwrhf Nwxzrjwf iarbobt wbj O iotmy haoy el xeil yb klipfls It is early Saturday morning and I might just be able to deliver

ynm jmzzmt zc zon wddm pevro hvoonov. Po avo ef edv paj be the letter to the good horse breeder. We are on our way to

Svolafn. Haryovqfego rct ifd tshye hgy uedm. V'p ihe ugyr stn, Ireland. Baskerhound has cut short our stay. I'm not sure why,

sdksyf fufg vu sgtu hwzy uvnzyzlm haivc h yxmdj omnqwdzijamn except that he made this decision after a short conversation

xajy Wnojuwn Emvkmdn, nyoxe nc Xu Pjabon. Dxezkeb az jqpac with Donaldo Rumtupo, owner of El Casino. Perhaps he knows

mbmn vqp mha sqyerj, tpn E zqptn en. that you are coming, but I doubt it.

Ca daayd dpdgeseqpdxv cnhhw. "Odc Uzghhf sh Asedk," fe He seems suspiciously happy. "The Cliffs of Moher," he

hqzh ltxxivn gji hsxfj hkti nehtkwoh, "uji Afmnnl yn Gykjq. Ezy says rubbing his hands with pleasure, "The Cliffs of Moher. You

kngg gntj wlki, Kcca, O wi nzrk." will like them, Ecco, I am sure."

O wi bax. Dzx pahhal ik xa Orkhwbj. If bkvx hkxxkr lohh dk I am not. But follow me to Ireland. My next letter will be

ob xml Vxjlo jaolaj pc Dbsv. P nygm kylm y ozgra ds hrqrarew ra in the Kames museum in Cork. I have made a habit of visiting it

opofoiov S'm sf bqp bwpb. Kfe qtmm utgo crq ifxcdgx dg jq c whenever I'm in the area. You will find the curator to be a

tdxchzq jfd tuhiqxq ncpl hcoqp Chhq G'Ighhqnn. Ngicn wqgwnq strange but sincere lady named Anne O'Connell. Local people

dsvib uts'v kzegn twfu fqq vub hgre kz Ylmg xhklu mgboyldx yl think she's crazy with all her talk of Inca stone carvings in

Yburglt. Njh xwv zy hm lkiyihmuzme evmvhslezyi. Ivss xwd rml idw Ireland. But she is an outstanding genealogist. Tell her you are

jdranf jm banv rmld omlzan Aziio M'Omnnwtt. Zyx ybuu gbrx snm trying to find your cousin Isaac O'Connell. She will give you

kzy poly. the note.

U J

Note the mistake at Ca daayd dpdgeseqpdxv cnhhw</tt> (He seems suspiciously happy</tt>).

After the C</tt>, the code was supposed to change, but it stayed on code $17$ until the next occurrence of h</tt>