Cryptography Reference
In-Depth Information
2.2.
FEODQFZJYOYFGPYHNOTOZKAMSNDJEIOT
.
This is a quote from
Arthur Schopenhauer (1788-1860)
taken from
“The
World as Will and Idea”
, published in 1819. Schopenhauer was a German
philosopher.
2.3.
HGGTFOUAOZFUEQKTIEOHTGNHHUZV
.
This, and the completion of it in Exercise 2.4 below, is a quote from
John
Fitzgerald Kennedy (1917-1963)
taken from one of his speeches. Kennedy
was the 35th President of the United States until his assassination. Note
that most modern-day presidents used ghost writers. Among Kennedy's
writers were Theodore Sorenson, Arthur Schlesinger, Jr.
(
see Exercise
2.5
)
, and John Kenneth Galbraith
(
see Exercise 2.6
)
, who wrote most of
Kennedy's best-known quotes.
2.4.
RGGJUGYFOUAOZROEPUNKUYKEWZGU
,
See Exercise 2.3.
2.5. Use the keyphrase given in Example 2.2 on page 75, and employ Kasiski's
method to the plaintext given below to show that the keylength is four.
“The only certainty in an absolute system is
the certainty of absolute abuse.”
(
Hint: Look for the repeated groups of ciphertext
UOVRSS
and
YR
.
Then compute the
gcd
of their respective distances.
)
The above is a quote from
Arthur Schlesinger Jr. (1917-)
taken from
an address he gave to the
Indian Council of World Affairs in 1962
. The
balance of the quote is:
“Injustice and criminality are inherent in a system
of totalitarian dictatorship”
. Schlesinger is an American educator and
historian
(
see also Exercise 2.3.
)
In Exercises 2.6-2.9, use the ADFGVX Field cipher method described on
pages 80 and 81 to decrypt the ciphertext in each case, where the key to
be used is given in each exercise.
2.6. In this exercise use the key
SUBNETWORK
.
FAAAXDAG DFFFFFFA FXGFFFAV GXGVAFGF
VFVFFAFA XFFFVGDX VFFXFXFX AFGGGVFX
GXGFGXGA AXAFAXXX
(
Hint: Put each of the above ten rows as individual columns corresponding
to the numbering of the letters in the key as done in Example 2.3 on page
81.
)
This is a quote from
John Kenneth Galbraith (1908-)
taken from Chapter
1of
“The A^uent Society” (1958)
. Galbraith is a Canadian-born Amer-
ican economist. Also see Exercise 2.3.
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