WGU COURSE C839 INTRO TO CRYPTOGRAPHY
QUIZLET BY BRIAN MACFARLANE
EXPECTED QUESTIONS WITH VERIFIED ANSWERS
Question 1.
Symmetric cipher that applies DES three times to each block of data during the encryption process.
ANSWER
Triple DES (3DES)
Question 2.
The ticket that is granted during the authentication process.
ANSWER
Ticket Granting Ticket (TGT)
Question 3.
Each block of plaintext is XORed with the XOR of the previous plaintext block and the previous
ciphertext block before being encrypted. As with CBC mode, an initialization vector is used in the first
block.
ANSWER
Propagating Cipher Block Chaining (PCBC)
Question 4.
Transposition processes used in encryption functions to increase randomness.
ANSWER
Diffusion
,Question 5.
Cryptographic attack that exploits the mathematics behind the birthday problem in the probability
theory forces collisions within hashing functions.
ANSWER
Birthday attack
Question 6.
The total number of co prime numbers for a number n
ANSWER
Euler's Totient
Question 7.
The number of positive integers less than or equal to n that are co-prime to n is called the _____________
of n.
So for the number 6, 4 and 5 are co-prime with 6. Therefore, ______________ = 2.
ANSWER
Euler's totient
Question 8.
In information theory,__________ is a measure of the uncertainty associated with a random variable.
ANSWER
entropy
Question 9.
This algorithm was published in a paper by Ross Anderson as an improvement on FISH. Anderson
showed that Fish was vulnerable to known plaintext attacks. It is both faster and stronger than FISH.
ANSWER
PIKE
,Question 10.
_____ uses at least two different shifts, changing the shift with different letters in the plain text.
A Atbash
B multi-alphabet encryption
C Scytale
D Caesar cipher
ANSWER
B
Question 11.
_________ uses a block size of 128 bits and key sizes up to 256 bits. It is a Feistel cipher. It was designed
by Bruce Schneier, John Kelsey, Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson.
ANSWER
Twofish
Question 12.
In 1980, Martin Hellman described a cryptanalytic time-memory trade-off which reduces the time of
cryptanalysis by using pre-calculated data stored in memory.
Essentially, these types of password crackers are working with pre-calculated hashes of all passwords
available within a certain character space, be that a-z, or a-zA-z, or a-zA-Z0-9, etc.
These files are called ___________________. They are particularly useful when trying to crack hashes. Since
a hash is a one-way function, the way to break it is to attempt to find a match.
The attacker takes the hashed value and searches the rainbow tables seeking a match to the hash. If
one is found, then the original text for the hash is found.
A popular hacking tool is Ophcrack.
ANSWER
Rainbow Tables
, Question 13.
What is X.509?
A The standard for PGP certificates
B The standard for encrypting email
C The standard for FIPS 186
D The standard for digital certificates
ANSWER
D
Question 14.
_______________ is the worst enemy of security, and it almost always comes in the form of features or
options.
ANSWER
Complexity
Question 15.
Designed by NSA for the clipper chip, ___________ uses an 80-bit key to encrypt or decrypt 64-bit data
blocks. It is an unbalanced Feistel network with 32 rounds.
ANSWER
Skipjack
Question 16.
A _____ is a function that takes a variable-size input m and returns a fixed-size string.
A Symmetric cipher
B Hash
C Asymmetric cipher
D Feistel
ANSWER
B
QUIZLET BY BRIAN MACFARLANE
EXPECTED QUESTIONS WITH VERIFIED ANSWERS
Question 1.
Symmetric cipher that applies DES three times to each block of data during the encryption process.
ANSWER
Triple DES (3DES)
Question 2.
The ticket that is granted during the authentication process.
ANSWER
Ticket Granting Ticket (TGT)
Question 3.
Each block of plaintext is XORed with the XOR of the previous plaintext block and the previous
ciphertext block before being encrypted. As with CBC mode, an initialization vector is used in the first
block.
ANSWER
Propagating Cipher Block Chaining (PCBC)
Question 4.
Transposition processes used in encryption functions to increase randomness.
ANSWER
Diffusion
,Question 5.
Cryptographic attack that exploits the mathematics behind the birthday problem in the probability
theory forces collisions within hashing functions.
ANSWER
Birthday attack
Question 6.
The total number of co prime numbers for a number n
ANSWER
Euler's Totient
Question 7.
The number of positive integers less than or equal to n that are co-prime to n is called the _____________
of n.
So for the number 6, 4 and 5 are co-prime with 6. Therefore, ______________ = 2.
ANSWER
Euler's totient
Question 8.
In information theory,__________ is a measure of the uncertainty associated with a random variable.
ANSWER
entropy
Question 9.
This algorithm was published in a paper by Ross Anderson as an improvement on FISH. Anderson
showed that Fish was vulnerable to known plaintext attacks. It is both faster and stronger than FISH.
ANSWER
PIKE
,Question 10.
_____ uses at least two different shifts, changing the shift with different letters in the plain text.
A Atbash
B multi-alphabet encryption
C Scytale
D Caesar cipher
ANSWER
B
Question 11.
_________ uses a block size of 128 bits and key sizes up to 256 bits. It is a Feistel cipher. It was designed
by Bruce Schneier, John Kelsey, Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson.
ANSWER
Twofish
Question 12.
In 1980, Martin Hellman described a cryptanalytic time-memory trade-off which reduces the time of
cryptanalysis by using pre-calculated data stored in memory.
Essentially, these types of password crackers are working with pre-calculated hashes of all passwords
available within a certain character space, be that a-z, or a-zA-z, or a-zA-Z0-9, etc.
These files are called ___________________. They are particularly useful when trying to crack hashes. Since
a hash is a one-way function, the way to break it is to attempt to find a match.
The attacker takes the hashed value and searches the rainbow tables seeking a match to the hash. If
one is found, then the original text for the hash is found.
A popular hacking tool is Ophcrack.
ANSWER
Rainbow Tables
, Question 13.
What is X.509?
A The standard for PGP certificates
B The standard for encrypting email
C The standard for FIPS 186
D The standard for digital certificates
ANSWER
D
Question 14.
_______________ is the worst enemy of security, and it almost always comes in the form of features or
options.
ANSWER
Complexity
Question 15.
Designed by NSA for the clipper chip, ___________ uses an 80-bit key to encrypt or decrypt 64-bit data
blocks. It is an unbalanced Feistel network with 32 rounds.
ANSWER
Skipjack
Question 16.
A _____ is a function that takes a variable-size input m and returns a fixed-size string.
A Symmetric cipher
B Hash
C Asymmetric cipher
D Feistel
ANSWER
B
