41. What is the Caesar Shift? How many different possibilities are there when encoding clear text with
the Caesar Shift? What does this mean for the security of this encryption type?
a.
In cryptography, a Caesar cipher, also known as a Caesar's cipher, the shift cipher,
Caesar's code or Caesar shift, is one of the simplest and most widely known encryption
techniques. It is a type of substitution cipher in which each letter in the plaintext is
replaced by a letter some fixed number of positions down the alphabet. Alphabet shift +3.
For example, with a shift of 3, A would be replaced by D, B would become E, and so on.
The method is named after Julius Caesar, who used it to communicate with his generals.
As with all single alphabet substitution ciphers, the Caesar cipher is easily broken and in
practice offers essentially no communication security.
42. Decipher Julius Caesar’s message to Brutus (supposedly, he liked to use ROT 3): “Glg brx gr brxu
krphzrun, rk Euxwxv?”
a.
Did you do your homework, oh Brutus?
43. What is Simple Substitution? Explain how known frequency distributions of letters in a language
are used to break this cipher.
a.
Relies on permutation; each letter is substituted for another letter and needed a code book
to know substitutions, now a 26letter factorial alphabet
b.
In cryptography, a substitution cipher is a method of encryption by which units of
plaintext are replaced with ciphertext according to a regular system; the "units" may be
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 Spring '07
 Anderson
 Cryptography, Julius Caesar, Substitution cipher

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