Exam MCQ Flashcards
_______ is prevention of unauthorised use of a resource.
A) Authenticity
B) Access control
C) Reliability
D) Integrity
B) Access control
A common technique for masking contents of messages or other information traffic so that opponents cannot extract the information from the message is _______.
A) integrity
B) analysis
C) encryption
D) masquerade
C) encryption
_______ prevents or inhibits the normal use or management of communication facilities.
A) Passive attack
B) Replay
C) Denial of Service
D) Masquerade
C) Denial of Service
Using Caesar cipher with key 3, the ciphertext that corresponds to the plaintext “hello” is:
A) IFMMP
B) KHOOR
C) LIPPS
D) GDKKN
B) KHOOR
_______ attacks involve trying every possible key until an intelligible translation of the ciphertext into plaintext is obtained.
A) Brute-force
B) Block cipher
C) Transposition
D) Cryptanalysis
A) Brute-force
A technique referred to as a _______ cipher is a mapping achieved by performing some sort of permutation on the plaintext letters.
A) polyalphabetic
B) Caesar
C) monoalphabetic
D) transposition
D) transposition
The majority of network-based symmetric cryptographic applications make use of _______ ciphers.
A) linear
B) differential
C) transposition
D) block
D) block
_______ means that the statistical structure of the plaintext is dissipated into long-range statistics of the ciphertext.
A) Diffusion
B) Confusion
C) Transposition
D) Substitution
A) Diffusion
The last round in AES does not include _______ transformation.
A) Substitute bytes
B) AddRoundKey
C) MixColumns
D) ShiftRows
C) MixColumns
The word size in AES key expansion is _______ bytes.
A) 2
B) 4
C) 8
D) 16
D) 16
In _______ mode of operation, the input to the encryption algorithm is the XOR of the next block of plaintext and the preceding block of ciphertext.
A) ECB
B) CTR
C) OFB
D) CBC
D) CBC
Both _______ modes produce output that is independent of both the plaintext and the ciphertext. This makes them natural candidates for stream ciphers that encrypt plaintext by XOR one full block at a time.
A) OFB and CTR
B) CBC and ECB
C) ECB and OFB
D) CTR and CBC
A) OFB and CTR
The concept of public-key cryptography evolved from an attempt to attack two of the most difficult problems associated with symmetric encryption: _______ and digital signatures.
A) reverse engineering
B) licensing costs
C) key generation
D) key distribution
D) key distribution
To provide authentication using public-key encryption, A can send a message to B as follows:
The most common choice of e in RSA public key is 65537 (216+1) because
A) it is easy for programmers to remember
B) it requires only 17 bits to store
C) it has only two 1 bits
D) it is difficult to calculate its corresponding private key d
C) it has only two 1 bits