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Each of the six extracts is encrypted with a simple
substitution cipher
In the first extract, this is a straightforward shift: P=A, Q=B,
R=C etc.
In extracts two to six, the ciphertext alphabet is formed by taking
a keyword, removing those letters that occur more than once in the
keyword, and then adding all remaining letters in alphabetical order.
In extract two, the keyword is MURDERS IN THE RUE MORGUE. By taking
out those letters that are repeated in the keyword, we are left
with: MURDESINTHOG. We then add all unused letters in alphabetical
order to give us: MURDESINTHOGABCFJKLPQVWXYZ.
Finally, the alphabet is shifted to give the keyword PUZZLE as
the encryption of A in each alphabet in turn (as read down the left
hand side of the grid).
Answers
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1
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And Joshua the son of Nun sent two men secretly from Shittim
as spies, saying, "Go, view the land, especially Jericho."
Joshua chapter 2. The Bible, c.550 BC. (An early reference
to intelligence gathering.)
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2
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Many years ago I contracted an intimacy with a Mr. William
Legrand. He was of an ancient Huguenot family, and had once
been wealthy; but a series of misfortunes had reduced him
to want.
Edgar Allan Poe, Tales of Mystery and Imagination: The Gold
Bug. The Dollar Newspaper, Philadelphia, 1843. (The first
extensive treatment of cryptanalysis in fiction.)
Keyword: MURDERS IN THE RUE
MORGUE (another famous short story by Poe).
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3
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Holmes had been seated for some hours in silence with
his long, thin back curved over a chemical vessel in which
he was brewing a particularly malodorous product.
Sir Arthur Conan Doyle, The Adventure of the Dancing Men,
The Strand Magazine, 1903. (Another fictional example of a
substitution cipher.)
Keyword: MYCROFT HOLMES
(Sherlock Holmes's brother).
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4
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The American handed Leamas another cup of coffee and said,
"Why don't you go back and sleep? We can ring you if he shows
up."
John Le Carre, The Spy Who Came In From The Cold. Victor
Gollancz, 1963. (The third in the series of books featuring
George Smiley, one of the best known fictional agents.)
Keyword: GEORGE SMILEY
(main character in this series of books).
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5
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An Act to make provision about the Secret Intelligence
Service and the Government Communications Headquarters, including
provision for the issue of warrants and authorisations
(The Act of Parliament allowing GCHQ to operate, and defining
its accountability to Parliament and the public.)
Keyword: ELIZABETH THE SECOND
(signatory of the Act), Intelligence Services Act 1994.
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6
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On the morning of Wednesday, 15 October 1586, Queen Mary
entered the crowded courtroom at Fotheringhay Castle.
(Some editions of this book list the day as Saturday)
Simon Singh, The Code Book. Fourth Estate, 1999. (Singh's
book is a recent tour de force on the subject of cryptography.)
Keyword: FOURTH ESTATE
(publisher).
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Solution Grid
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A |
B |
C |
D |
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F |
G |
H |
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J |
K |
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M |
N |
O |
P |
Q |
R |
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V |
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X |
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Z |
| 1 |
P |
Q |
R |
S |
T |
U |
V |
W |
Z |
Y |
Z |
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B |
C |
D |
E |
F |
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H |
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N |
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| 2 |
U |
R |
D |
E |
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H |
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G |
A |
B |
C |
F |
J |
K |
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P |
Q |
V |
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X |
Y |
Z |
M |
| 3 |
Z |
M |
Y |
C |
R |
O |
F |
T |
H |
L |
E |
S |
A |
B |
D |
G |
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J |
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P |
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| 4 |
Z |
G |
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O |
R |
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M |
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L |
Y |
A |
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C |
D |
F |
H |
J |
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N |
P |
Q |
T |
U |
V |
W |
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| 5 |
L |
I |
Z |
A |
B |
T |
H |
S |
C |
O |
N |
D |
F |
G |
J |
K |
M |
P |
Q |
R |
U |
V |
W |
X |
Y |
E |
| 6 |
E |
S |
A |
B |
C |
D |
G |
I |
J |
K |
L |
M |
N |
P |
Q |
V |
W |
X |
Y |
Z |
F |
O |
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R |
T |
H |
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