Challenge Solutions

Chapter 2: Herbert Yardley’s first challenge

The following encryption table was used:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
BCDEFGHIJKLMNOPQRSTUVWXYZA

Cipher: A Caesar cipher with key -1 was used (A->Z, B->A, C->B, …).

Plaintext: totally disabled longitude forty latitude seventy three

Chapter 2: A series of newspaper advertisements from 1900

The following encryption table was used:

ABCDEFGHIJKLMNOPQRSTUVWXYZ
OPQRSTUVWXYZABCDEFGHIJKLMN

 

Cipher: A Caesar cipher with key 14 (A->O, B->P, C->Q, …) was used for the encrypted passages.

Plaintexts:

ALICE R.P. Congratulate you. I do not forget but think of you very much and wonder if we shall meet in six or seven weeks. Tuesday 27th March 1900

ALICE R.P. How nice of you to remember. Will certainly meet you. Always thinking of you. Thursday 29th March 1900

ALICE R.P. Am so looking forward to it. Want to see you more than i can tell you. Will let know in about five weeks time. Monday 2nd April 1900

ALICE R.P. Shall wait portland dp station thursday five clock should much like see you. Thursday 17th May 1900

Chapter 3: A prison code

The following word stands for MARK:
Plaintext:

Hey Mark,
So I could not find a generator online but there is an Aurebesh font you can download for both Mac and PC and install. I’ve been reading into how to take pictures of individual snowflakes. It is an amazing process. After the Holiday I’ll send you in an article about it with some examples.

Chapter 3: A postcard

Hint: ABC in the transcribed ciphertext stands for FRI.

 

 

Plaintext:

Fri Night
How are you Ethel
Suppose you are
st(u)dying ton(i)ght

I have been trying
to flourish a
little. Have
been out breaking
roads this
afternoon for the
wagons. Good night (RR)LW

 

Chapter 3: Another postcard

The following word stands for HELLO:

Key:

Plaintext:

Hello Nellie This rose was raised in our backyard. Is it not beautiful? Elizabeth is in two places at once, on running creek, and on the map.
Ta-Ta – F.M.S.

Chapter 3: Friedman's wedding centennial nickel

The keyword BANDJ was used to scramble the alphabet. BANDJ is derived from “Bill and Jew-Lee”, the first names of Bill Briere and Jew-Lee Lann-Briere, who created this puzzle.

The ciphertext trigraph KZW stands for THE.

The following substitution table was used:

ABCDEFGHIJKLMNOPQRSTUVWXYZ
STUVWXYZBANDJCEFGHIKLMOPQR

Plaintext:

CENTENNIAL OF THE
WEDDING

OF ELIZEBETH AND
WILLIAM

1917 * FRIEDMAN * 2017

Chapter 3: An aristocat from the ACA

The keyword DEBIAN was used to scramble the alphabet.

The ciphertext trigraph JYV stands for THE.

 

The following substitution table was used:

ABCDEFGHIJKLMNOPQRSTUVWXYZ
RSTUVWXYZDEBIANCFGHJKLMOPQ
Plaintext:
FOX IN THE HEN HOUSE AND FOX GUARDING THE HEN HOUSE ARE THE SAME. THUS HE WHO OWNS THE HEN HOUSE MUST BE DEAF, BLIND, OR BOTH

Chapter 4: Rudyard Kipling’s encrypted message

Most ciphertext symbols look similar as their plaintext counterparts.

The word

stands for THE.

The following substitution table was used:

 

Plaintext:

Left side:

This is the stori of Taffimai all ritten out on an old tusk. If u begin at the top left hand corner and go on to the right u can see for urself things as the happened.

Right side:

The reason that I spell so queerli is becase there are not enough letters in the Runic alphabet for all the ourds that I ouant to use to u o beloved.

 

Chapter 4: NSA’s second Monday challenge

The ciphertext trigraph FRP stands for NSA. As the text needs to be read backwards, this means that actually PRF stands for ASN.

ABCDEFGHIJKLMNOPQRSTUVWXYZ
PHQGIUMEAJLNOFDXBKRCVSTZWY

Plaintext:

NSA is looking for intelligent, imaginative critical thinkers who can contribute innovative ideas to solve our most difficult challenges.

Chapter 5: An encrypted postcard

6

GT stands for the French word MA (“my”).

Key:

ABCDEFGHIJKLMNOPQRSTUVWXYZ
GHIJKLMNOPQRSTUVWXYZABCDEF

Plaintext:

MA CHERE PETITE IDA,
AI JE MANQUE DE PAROLE. TU VOIS QUE JE PENSE A TOI. ET TOI M’AS TU OUBLIE. JE T’ENVOIE DES MILLIERS DE BAI[S]ERS SUR TES PETITES LEVERES ET SUR TOUT DE QUE J’AIME. ECRIS MOI

Translation:

My dear little Ida,

Have I broken my promise. You see that I have thought of you. And you, have you forgotten me? I send you thousands of kisses on your little lips and on everything I love. Write me.

Chapter 5: The third NSA Monday challenge

“nby” stands for “los”.

ABCDEFGHIJKLMNOPQRSTUVWXYZ
?OIYPRVNH?BCAL?F?ETG?U?DSM

Plaintext:

Los cient(i)ficos de la computaci(o)n tienen la oportunidad de ampliar sus iniciativas, habilidades y talentos para aprender y ser imaginativos.

Translation:

Computer scientists have the opportunity to broaden their innitiative, skills, and talents to learn and be imaginative.

Chapter 5: Christlieb Funk's challenge cryptogram

The following word stands for EINE (female indefinite article):

With the following table, the ciphertext can be decrypted:

Plaintext:

SOLLTE DIESES MEIN BUCH BEYFALL
FINDEN SO WIRD ES MIR EINE
AUFMUNTERUNG SEYN NOCH MEHR
ÄHNLICHE AUFFALLENDE PHYSEKALISCHE
EXPERIMENTE DIE ZUR ERKLÄRUNG
VERSCHIEDENER PRÄTENDIRTER WUNDER
DIENEN BEKANNT ZU MACHEN DENN DIE
MATERIE IST BEY WEITEN NOCH NICHT
ERSCHÖPFT UND ICH HABE GEGENWÄRTIG
NUR EINIGES ERKLÄREN WOLLEN ES
IST MIR NICHTS MEHR ÜBRIG ALS
MICH DEM WOHLWOLLEN DES GENEIGTEN
LESERS ZU EMPFEHLEN GESCHRIEBEN IN
DER LEIPZIGER OSTERMESSE IM IAHRE
EIN TAUSEND SIEBEN HUNDERT DREY UND
ACHTZIG

Translation:

If this book should be successful, it will be my pleasure to make known more physical expriments that serve to explain alleged miracles. This matter is by far not exhausted, and I have so far only explained a part of it. Apart from this, I can only send my regards to my readers. Written during the Leipzig Easter Fair in the year 1783.

Chapter 6: A message to the Zodiac Killer

The same symbols are used in this cryptogram as in the first Zodiac message (Z408).

Plaintext:

SODIAC CALL LIBRA FOUR THREE THREE ONE OH SEVEN SEVEN

Chapter 6: Edgar Allan Poe’s second challenge

The third word, OGXEW, stands for EARLY.

Plaintext:

It was early spring, warm and sultry glowed the afternoon. The very breezes seemed to share the delicious langour of universal nature, are laden the various and mingled perfumes of the rose and the -essaerne (?), the woodbine and its wildflower. They slowly wafted their fragrant offering to the open window where sat the lovers. The ardent sun shoot fell upon her blushing face and its gentle beauty was more like the creation of romance or the fair inspiration of a dream than the actual reality on earth. Tenderly her lover gazed upon her as the clusterous ringlets were edged (?) by amorous and sportive zephyrs and when he perceived (?) the rude intrusion of the sunlight he sprang to draw the curtain but softly she stayed him. “No, no, dear Charles,” she softly said, “much rather you’ld I have a little sun than no air at all.”

Chapter 7: Mount Everest telegram

Google the codewords.
Title of code book used:
Universal cryptographic phrase book 6th edition

The codebook can be found here.

Plaintext:
MALLORY IRVINE KILLED IN LAST ENGAGEMENT, REMAINDER ARRIVED ALL IN GOOD ORDER.

Chapter 8: Schooling challenge

76 69 57 55 65 59 68 87 77 22 75 68 87 88 75 43 67 77 58 65 96
44 54 42 11 33 44 44 54 42 11 33 44 44 54 42 11 33 44 44 54 42
--------------------------------------------------------------
32 15 25 44 32 15 24 33 35 11 42 24 43 34 33 32 34 33 14 11 54

Plaintext:

MEET ME IN PARIS ON MONDAY

Literature: Craig Bauer: Unsolved! Princeton University Press, Princeton 2017, p. 137

Chapter 8: A German radio message from the Second World War

The mathematical constant the key is derived of is pi.

The key length is 7.

The plaintext contains the word STOP.
Key:
3141592 (the first seven digits of pi), equivalent with DBEBFJC (if A=0, B=1, C=2, …)
 
Plaintext:
ACHT STOP ERHIELTEN EURE NACHRICHT VOM ZWEITEN APRIL STOP ERWARTEN EUCH ZU VORGESCHLAGENEN ZEITEN STOP GABEN EUCH VOM DREISSIGSTEN MAERZ BIS NEUNTEN APRIL NUR BUCHSTABENGRUPPEN OHNE SINN STOP BEZUEGLICH BETREUUNG ABWARTET NACHRICHT STOP CARLOS

Chapter 9: Love in Code

Read each word backwards.

Plaintext:

TRUST ME, BOYS. I QUEEN OF LAMPEDUSA

 

Chapter 9: The Friedmans’ love messages

Ciphertext 1: Down one column, up the next

Ciphertext 2: Up one column, down the next

Plaintext 1:

I LOVE YOU VERY MUCH I SHOULD SAY SO!!

Plaintext 2:

JE T’ADORE MON MARI!!

Translation: “I admire my husband.”

Chapter 9: Agony column

Write the first message in lines of eleven:
Lkeoisvstes
oeemldyodbv
ensedtpliaa
naeglmslyhb
rmnebemrsea
outfWeyrwoi
hoaeuvnleye
Split the second message into two, and write each part in lines of three:
Ieg    rcg
cne    dhl
hdn    ihu
hao    sac
ass    cbk
bis    hei
e      e

Advertisement 1:

When written in lines of 11 (see hint 1), read columns 1, 4, 7, 10, 2, 5, 8, 11, 3, 6, 9:

Love kisses to my beloved deep and lasting shall be my remembranes of you. Write when you leave.

Advertisement 2:

When split and written in lines of 3 (see hint 2), read columns 1, 3, 2 of each part:

Ich habe genossen das irdische gluck ich habe

These are the first eight words of a quote by German poet Friedrich Schiller:

Ich habe genossen das irdische Glück, ich habe gelebt und geliebet!

Translation: “I have enjoyed the happiness on earth, I have lived and loved.”

Chapter 9: Yardley's 11th ciphergram

After you counted, what is the square root?

A six by six table

When written in lines of six, the ciphertext looks as follows:

tskgla
atyilt
lpasah
lmdplg
ieneai
wtuenn

Now read each column from bottom to top:

will attempt sunday keep signal all night a

The “a” at the end is used for padding.

Chapter 9: Edgar Allan Poe's first challenge

The following three letters stand for DNA (mind that each word is written backwards):

Plaintext:

The soul secure in her existence smiles at the drawn dagger and defies its point. The stars shall fade away, the sun himself grow dim with age and nature sink in years, but thou shall flourish in immortal youth, unhurt amid the war of elements, the wreck of matter and the crush of worlds.

For more information, check here: http://cryptiana.web.fc2.com/code/poe2.htm

Chapter 9: IRA messages

Try lines of 12.

 

The key word is: INCANDESCENT

INCANDESCENT
------------
TWOTICKETSFO
RHOTELCECILW
ERESECUREDAN
DTHEREFOURBO
MBSWEREIGNIT
EDBUTTHREEFA
ILEDANDTHEOT
HERSIMPLYSPL
UTTEREDANDWA
SINEFFECTIVE

Plaintext:

TWO TICKETS FOR HOTEL CECIL WERE SECURED AND THERE FOUR BOMBS WERE IGNITED BUT THREE FAILED AND THE OTHER SIMPLY SPLUTTERED AND WAS INEFFECTIVE

 

Chapter 10: IRA message

There are 12 columns in this transposition.

The plaintext contains the following letter string:

PITIABLECONSIDERING

The keyword is: INCANDESCENT

Plaintext:

THE BOMBS WERE HOPELESS AND PITIABLE CONSIDERING THE RISR A EXPENCE INCURRED
 
The bombs were hopeless and pitiable, considering the risk and expence incurred.

Chapter 11: The Friedman’s Christmas card

The plaintext contains the word TELEPHOTOGRAM.

Plaintext:

FOR CHRISTMAS GREETINGS IN 28 WE USE A MEANS QUITE UP-TO-DATE. A CRYPTO TELEPHOTOGRAM HERE BRINGS YOU WORD OF X-MAS CHER.

Chapter 11: Jew-Lee and Bill’s Cryptocablegram

Here’s the ciphertext with the substituted letters:

The grille is the same as in the previous challenge (i.e., the grille used by the Friedmans also solves this ciphertext).

Plaintext:

TO THE FRIEDMANS: MILESTONES MEMORIES MOMENTUM CLINKING GLASSES A LUCKY KISS AND AULD LANG SYNE!

Chapter 11: MysteryTwister C3 challenge

Check here for the original challenge on MysteryTwister C3.

Sorry, we can’t provide the solution for this challenge.

We took this cryptogram from the MysteryTwister C3 (MTC3) website. MTC3 participants will get points for solving it. Providing the solution here would enable them to cheat.

Chapter 11: Kerckhoffs' cryptogram

The plaintext contains the word “Attaque”.

Here’s the grille that was used:

Plainext:

Une Attaque Simulee Aura Lieu Demainmatin

Translation: A test attack will take place tomorrow morning.

Chapter 12: National Treasure: Book of Secrets

The plaintext starts with the word LABOULAYE.

The following matrix was used:

DEATH
BCFGI
KLMNO
PQRSU
VWXYZ

Plaintext:

LABOULAYE LADY WILL LEAD TO CIBOLA TEMPLES OF GOLD

“Laboulaye Lady” referrers to the French Statue of Liberty in Paris, France.

Chapter 13: A birthday card

The plaintext is taken from the lyrics of a well-known song.

Plaintext:

Happy Birthday to You, Happy Birthday to You. Happy Birthday, Dear Peter, Happy Birthday to You.

Chapter 14: Dan Brown’s book cipher challenge

20=E, 11=U, 11=U, 68=N, 1=R, 10=S, 11=U, 61=P, 5=M, 8=L, 73=B, 11=U

Latin

Got any American coins in your pocket?

Plaintext:

E PLURIBUS UNUM

Translation: Out of many one

Chapter 14: Dictionary code challenge

Here’s a list with the 10,000 most common Engish words:

https://www.mit.edu/~ecprice/wordlist.10000

0619 stands for AT
8928 stands for THE
9216 stands for TREE

Plaintext:

START AT THE OAK TREE NEXT TO C A M D E N BRIDGE THREE KILOMETERS SOUTH OF THE POWER PLANT FOLLOW THE ROAD OVER THE BRIDGE AGAIN ABOUT ONE KILOMETER TAKE A LEAVING AND WALK ALONG THE WALLS AFTER SIX HUNDRED METERS YOU WILL REACH A MALL IN THE CENTER OF IT THERE IS A STONE CRYSTAL ON THE REAR SIDE OF IT YOU WILL FIND A WOODEN CASSETTE CONTAINING A DICE THAT WILL HELP YOU TO DECRYPT THE NEXT MESSAGE

Chapter 15: Another steganographic message by the Friedmans

Here’s a hires version of the passage in question:

Text snipped from

The Bacon cipher was used:

In the following scan, the marks show that the passage in italics is written in two different fonts:

The two fonts form the following pattern:

ABAAA AAABB ABAAA AAABB ABBAA ABBAB BAABA BABAA BAAAA ABAAA BAABA AABAA BAABA AABBB AABAA ABBBA ABABA BABBA BAAAB AABAB AAAAB AAAAA AAABA ABBAB ABBAA

Plaintext:

I did not write the plays. F. Bacon.

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