C839 exam with 100%
correct answers
Cryptography - answer Science of altering communication so that it
cannot be understood without a key
Mono-Alphabet Substitution Cipher - answer Algorithms that simply
substitute one character of cipher text for one character of plain
text, these are the most primitive algorithms
Caesar Cipher - answer Every letter is simply shifted a fixed number
of places to the left or to the right
Atbash Cipher - answer Hebrew cipher which substitutes the first
letter of the alphabet for the last, and the second letter for the
second-to-last, in other words, it simply reverses the alphabet.
Affine Cipher - answer Any single substitution alphabet ciphers
where each letter in the alphabet is mapped to some numeric value,
permuted with some relatively simple mathematical function, and
then converted back to a letter.
The formula for any basic cipher of this type is ax+b(modM), M
being the size of the alphabet, so for example Caeser cipher would
be 1x+3(mod26)
ROT13 Cipher - answer A single alphabet substitution cipher where
all characters are rotated 13 characters through the alphabet.
Scytale Cipher - answer Physical cylinder that was used to encrypt
messages. Turning the cylinder produced different ciphertexts.
correct answers
Cryptography - answer Science of altering communication so that it
cannot be understood without a key
Mono-Alphabet Substitution Cipher - answer Algorithms that simply
substitute one character of cipher text for one character of plain
text, these are the most primitive algorithms
Caesar Cipher - answer Every letter is simply shifted a fixed number
of places to the left or to the right
Atbash Cipher - answer Hebrew cipher which substitutes the first
letter of the alphabet for the last, and the second letter for the
second-to-last, in other words, it simply reverses the alphabet.
Affine Cipher - answer Any single substitution alphabet ciphers
where each letter in the alphabet is mapped to some numeric value,
permuted with some relatively simple mathematical function, and
then converted back to a letter.
The formula for any basic cipher of this type is ax+b(modM), M
being the size of the alphabet, so for example Caeser cipher would
be 1x+3(mod26)
ROT13 Cipher - answer A single alphabet substitution cipher where
all characters are rotated 13 characters through the alphabet.
Scytale Cipher - answer Physical cylinder that was used to encrypt
messages. Turning the cylinder produced different ciphertexts.
