D334 - Introduction To Cryptography Exam
|Actual Exam With 100% Verified
Questions And Correct Answers| Excellent
Scores
Dictionary-type attack - correct-answer-a brute force analysis
∉ - correct-answer-does not belong to
when an object is not in a set
∈ - correct-answer-Belongs to
when an object is within a set
⊆ - correct-answer-subset
subset has fewer elements or equal to the set
, P age |2
A ∪ B - correct-answer-union (objects that belong to set A or set B)
| - correct-answer-such that
A ∩ B - correct-answer-Intersection: in both A and B
Enigma Machine -Cypher 10 - correct-answer-Used a polyalphabetic substitution
cipher, which did not repeat within a reasonable time period, along with a secret
key. For the cracking of the Enigma cipher, the challenge was thus to determine
both the algorithm used and the key. Enigma's main weakness, though, was that
none of the plain text letters could be ciphered as itself.
Four-square cipher9 - correct-answer-Uses four 5 × 5 matrices arranged in a
square, are where each matrix contains 25 letters for encoding and decoding
operations.
One-time pad cypher8 - correct-answer-Cypher Code mapping that is only used
once.
, P age |3
Advantage: it is essentially unbreakable.
Disadvantage: it takes lots of work as you would have to generate the pad to be
used, each time.
Vigenere Cipher 7 - correct-answer-Polyalphabetic cipher that involves using a
different mapping, based on a keyword, for each character of the cipher. An
advantage of this type of cipher is that the same plaintext character is likely to be
coded to different mappings, depending on the position of the keyword, making
guessing more difficult.
Ceasar Cipher6 - correct-answer-Mono-alphabetic substitution cipher known as
"shift" cipher. Involves plaintext being replaced by a letter some fixed number of
positions down the alphabet. i.e., a Caesar Cipher using a shift of +3 would mean
a plaintext letter A would result in a ciphertext letter D (a shift of three positions
to the right in the alphabet)
Morse Code cipher 5 - correct-answer-Encoding method, rather than a cipher,
that works by translating characters into sequences of dots (.) and dashes (-)
Playfair Cipher 4 - correct-answer-5 × 5 matrix containing the alphabet less the
letter J. Cipher/decipher process consists of a set of rules outlining use of column
and row combinations.
, P age |4
BIFID Cipher 3 - correct-answer-Makes use of a grid and which maps the letters
into numeric values.
Rail Code Cipher 2 - correct-answer-Employs a method to scramble text by writing
it in a sequence across a number of rails.
Pig Pen Cipher 1 - correct-answer-Mono- alphabetic substitution cipher that
makes use of mapping plaintext characters to graphical characters rather than to
alphabetic ones. i.e. A=(pick a symbol), vs A=(pick a letter). Disadvantage: once
the mapping is known, it is difficult to keep the message secret.
Encryption - correct-answer-in simplest terms is changing plaintext into ciphertext
Decryption - correct-answer-The process of converting a ciphertext into plaintext.
AESCrypt - correct-answer-Encrypt individual files and encrypt full disks with
options such as Bitlocker and FileVault