2. The Adventure of the Dancing Men", one of
the 56 Sherlock Holmes short stories written
by British author Sir Arthur Conan Doyle, is
one of 13 stories in the cycle collected as The
Return of Sherlock Holmes. Doyle ranked
"The Adventure of the Dancing Men" third in
his list of his twelve favorite Holmes stories.
This is one of only two Sherlock Holmes short
stories where Holmes' client dies after
seeking his help. The other is "The Five
Orange Pips", part of The Adventures of
Sherlock Holmes
3. Hilton cubitt,squire,has come
to sherlock holmes for help in
solving a disturbing mystery.
Cubitt has found several
messages of coded letters
drawn in the form of dancing
men .
4. The messages are undecipherable to him but
extremly disturbing to his American wife
with a typical brilliance Sherlock Holmes
quickly realises the , the danger the
messages convey , and he and Watson travel
by rail To Cubitt estate.But is too late. Cubitt
has been found killed and it is believe that
Elsie shot him, although cannot be proved
bcause she herself is conscious near death’s
door working with the local inspector
,Holmes sets a trap for an american men
renting a room at a nearby farm . Holmes
must find the truth , Elsie may pay the
consequences… if she leaves
5. In cryptography, a cipher (or cypher) is
an algorithm for performing encryption or
decryption—a series of well-defined steps
that can be followed as a procedure. An
alternative, less common term
is encipherment. To encipher or encode is to
convert information from plain text into cipher
or code. In non-technical usage, a 'cipher' is
the same thing as a 'code'; however, the
concepts are distinct in cryptography.
Inclassical cryptography, ciphers were
distinguished from codes.
6. Codes generally substitute different length
strings of characters in the output, whilst
ciphers generally substitute the same
number of characters as are input.
When using a cipher the original
information is known as plaintext, and
the encrypted form as ciphertext. The
ciphertext message contains all the
information of the plaintext message, but
is not in a format readable by a human or
computer without the proper mechanism
to decrypt it.
7. The operation of a cipher usually depends
on a piece of auxiliary information, called
a key (or, in traditional NSA parlance,
a cryptovariable). The encrypting
procedure is varied depending on the key,
which changes the detailed operation of the
algorithm. A key must be selected before
using a cipher to encrypt a message.
Without knowledge of the key, it should be
extremely difficult, if not impossible, to
decrypt the resulting ciphertext into
readable plaintext.
8. VERSUS CODES
Within technical discussions, however,
the words "code" and "cipher" refer to
two different concepts.
However, codes have a variety of
drawbacks, including susceptibility
to cryptanalysis and the difficulty of
managing a cumbersome codebook.
Because of this, codes have fallen into
disuse in modern cryptography, and
ciphers are the dominant technique.
9.
10. Substitution of single letters separately—
simple substitution—can be demonstrated by
writing out the alphabet in some order to
represent the substitution. This is termed
a substitution alphabet. The cipher alphabet
may be shifted or reversed (creating
the Caesarand Atbash ciphers, respectively) or
scrambled in a more complex fashion, in which
case it is called a mixed alphabet or deranged
alphabet.
11. Traditionally, mixed alphabets may be created by
first writing out a keyword, removing repeated
letters in it, then writing all the remaining letters in
the alphabet in the usual order.
Using this system, the keyword "zebras" gives us the
following alphabets:
Plaintext
alphabet:ABCDEFGHIJKLMNOPQRSTUVWXYZCiph
ertext
alphabet:ZEBRASCDFGHIJKLMNOPQTUVWXYA
message of
flee at once. we are discovered! enciphers to
SIAA ZQ LKBA. VA ZOA RFPBLUAOAR!
12.
13. An early attempt to increase the difficulty of
frequency analysis attacks on substitution
ciphers was to disguise plaintext letter
frequencies by homophony. In these ciphers,
plaintext letters map to more than one
ciphertext symbol. Usually, the highest-
frequency plaintext symbols are given more
equivalents than lower frequency letters. In
this way, the frequency distribution is
flattened, making analysis more difficult.
14.
15.
16. Sherlock Holmes breaks a substitution cipher in "The
Adventure of the Dancing Men".
The Al Bhed language in Final Fantasy X is actually a
substitution cipher, although it is pronounced phonetically (i.e.
"you" in English is translated to "oui" in Al Bhed, but is
pronounced the same way that "oui" is pronounced in French).
The Minbari's alphabet from the Babylon 5 series is a
substitution cipher from English.
The language in Starfox Adventures: Dinosaur Planet spoken
by native Saurians and Krystal is also a substitution cipher of
the English alphabet.
