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
The principal object of a hash function is _______.
A) mapping messages
B) data compression
C) data confidentiality
D) data integrity
D) data integrity
A) collision
C) digital signature
_______ is denial of receipt of message by destination.
A) Disclosure
B) Masquerade
C) Source repudiation
D) Destination repudiation
D) Destination repudiation
________ is a function of the message and a secret key that produces a fixed-length value that serves as the authenticator.
A) MAC
B) Hash function
C) Symmetric encryption
D) SHA
A) MAC
The type of digital signature forgery where an attacker forges a signature for a particular message chosen by the attacker is called ______.
A) total break
B) universal forgery
C) selective forgery
D) existential forgery
C) selective forgery
The concept of ______ greatly reduces the number of keys that must be manually managed and distributed.
A) key distribution
B) key hierarchy
C) key generation
D) key termination
B) key hierarchy
Which of the following is true about public-key certificates?
A) They do not expire
B) They can only be used with RSA
C) They contain the private key of the user encrypted with the CA’s pubic key
D) They cannot be modified other than by the CA without being detected
D) They cannot be modified other than by the CA without being detected
Presenting or generating authentication information that corroborates the binding between the entity and the identifier is the ______ step.
A) identification
B) clarification
C) binding
D) verification
D) verification
To cope with a replay attack, party A, expecting a fresh message from B, first sends B a nonce and requires that the subsequent message received from B contain the correct nonce value. This process is called ______.
A) counter replay
B) fresh nonce
C) challenge/response
D) one-way authentication
C) challenge/response
Kerberos ______ issues tickets to users who have been authenticated to AS.
A) realm
B) TGS
C) AS
D) principal
B) TGS
TLS ______ Protocol provides confidentiality and message integrity for TLS connections.
A) Record
B) Privacy
C) Handshake
D) Change Cipher Spec
A) Record
One of the most useful features of SSH is ______, which allows converting any insecure TCP connection into a secure SSH connection.
A) TCP security
B) TCP conversion
C) HTTPS
D) Port forwarding
D) Port forwarding
______ mode authenticates IP payload and selected portions of IP header.
A) AH Transport
B) AH Tunnel
C) ESP Transport
D) ESP Tunnel
A) AH Transport
______ is a computer program that can run independently and can propagate a complete working version of itself onto other hosts on a network.
A) Logic bomb
B) Exploit
C) Worm
D) Auto-rooter
C) Worm
