A message is authentic and digitally signed if sent with:
a message digest/hash encrypted with the receiver’s public key
a message digest/hash encrypted with the receiver’s private key
a message digest/hash encrypted with the sender’s public key
a message digest/hash encrypted with the sender’s private key
Which of the following issues is not addressed by Kerberos:
availability.
privacy.
integrity.
authentication.
In Asymmetric-Key Cryptography, two keys, e and d, have a special relationship to
Others
Data
Keys
Each other
Substitutional cipers are
Monoalphabatic
Semialphabetic
Polyalphabetic
None of the above
Both monoalphabatic and polyalphabetic
Heart of Data Encryption Standard (DES), is the
Cipher
Rounds
Encryption
DES function
DES stands for
Data Encryption Standard
Data Encryption Subscription
Data Encryption Solutions
Data Encryption Slots
In symmetric key cryptography, key used by sender and receiver is
Shared
Different
two keys are used
None
In symmetric-key cryptography, key(s) used for encryption and decryption is/are
Same
Private
Public
Keys used in cryptography are
secret key
private key
public key
All of them
None of them
Cryptography can provide
entity authentication
nonrepudiation of messages
confidentiality
Advanced Encryption Standard (AES), has three different configurations with respect to number of rounds and
Data Size
Round Size
Key Size
Encryption Size
Cryptography algorithms (ciphers) are divided into
two groups
four groups
one single group
In Cryptography, original message, before being transformed, is called
Simpletext
Plaintext
Emptytext
Filledtext
SHA-l has a message digest of
160 bits
512 bits
628 bits
820 bits
A hash function guarantees integrity of a message. It guarantees that message has not be
Replaced
Over view
Changed
Left
To check integrity of a message, or document, receiver creates the
Cipher text
Hash
Hyper Text
Finger Print
A digital signature needs a
private-key
shared-key
public-key
Encryption and decryption provide secrecy, or confidentiality, but not
Authentication
Integrity
Frames
Confidentiality
When data must arrive at receiver exactly as they were sent, it is called
Message Confidentiality
Message Integrity
Message Splashing
Message Sending
In Message Integrity, SHA-l hash algorithms create an N-bit message digest out of a message of
512 Bit Blocks
1023 Bit Blocks
1001 Bit Blocks
1510 Bit Blocks
2024 Bit Blocks
Message privacy means that sender and receiver expect
Nonrepudiation
Message must be encrypted at sender site and decrypted at the
Sender Site
Site
Receiver site
Conferencing
In Asymmetric-Key Cryptography, although RSA can be used to encrypt and decrypt actual messages, it is very slow if message is
Short
Huge
Complex
Thin
An encryption algorithm transforms plaintext into
Simple Text
Plain Text
Empty Text
A transposition cipher reorders (permutes) symbols in a
block of packets
block of slots
block of signals
block of symbols
Ciphers of today are called round ciphers because they involve
Single Round
Double Rounds
Multiple Round
Round about
RSA stands for
Rivest, Shamir, Adleman
Roger, Shamir, Adrian
Robert, Shamir, Anthoney
Rivest, Shaw, Adleman
_______ is the science and art of transforming messages to make them secure and immune to attacks.
Cryptography
Cryptoanalysis
Crypt
The _______ is a number or a set of numbers on which the cipher operates.
cipher
nonce
secret
key
none of the above
In a(n) ________ cipher, the same key is used by both the sender and receiver.
symmetric-key
asymmetric-key
Public-key cryptography
RSA algorithm
In a(n) ________, the key is called the secret key.
In a(n) ________ cipher, a pair of keys is used
Private-key cryptography
DES algorithm
The Caesar cipher is a _______cipher that has a key of 3.
transposition
additive
asymmetric
substitution
The ________ cipher reorders the plaintext characters to create a ciphertext.
shift
A(n) ______ is a keyless substitution cipher with N inputs and M outputs that uses a formula to define the relationship between the input stream and the output stream.
S-box
P-box
T-box
SP-boxes
A(n) _______is a keyless transposition cipher with N inputs and M outputs that uses a table to define the relationship between the input stream and the output stream.
DES is a(n) ________ method adopted by the U.S. government.
decryption
encryption
DES has an initial and final permutation block and _________ rounds.
14
15
12
16
DES uses a key generator to generate sixteen _______ round keys.
32-bit
48-bit
56-bit
42-bit
64-bit
AES has _____ different configurations
two
three
four
five
AES has no configurations
One commonly used public-key cryptography method is the ______ algorithm.
RSS
RAS
RSA
RAA
DSS
The ________ method provides a one-time session key for two parties.
Diffie-Hellman
DES
AES
DSA
In symmetric cryptography, which of the following MUST be true:
The same key is used for encryption and decryption
Encryption and decryption take the same amount of time
Different algorithms are used for encryption and decryption
Cryptographic operations are one‐way, and not reversible
Message _____ means that the data must arrive at the receiver exactly as sent.
integrity
authentication
availability
Message _______ means that the receiver is ensured that the message is coming from the intended sender, not an imposter.
________ means to prove the identity of the entity that tries to access the system's resources.
Message authentication
Entity authentication
Message confidentiality
Message integrity
Digital signature cannot provide ________ for the message.
nonrepudiation
Challenge-response authentication can be done using ________.
symmetric-key ciphers
asymmetric-key ciphers
keyed hash function
keyless hash function
all of the above
A digital signature needs a(n)_________ system.
both symmetric- and asymmetric-key cryptography
The _______ criterion states that it must be extremely difficult or impossible to create the message if the message digest is given.
one-way property
collision-free property
both one-way and collision-free properties
Making sure that the data has not been changed unintentionally, due to an accident or malice, is:
Auditability
Availability
Identity
I have a company’s documents which are proprietary and a trade secret. How do I protect them from getting stolen?
Digitally sign the documents
Encrypt them using RSA or AES
Hash the data
Use decryption
Biometrics represents:
Something you know
Something you have
Something you are
All of the above
In asymmetric encryption
same key is used for encryption and decryption
different keys are used encryption and decryption
no key is required for encryption and decryption
none of the mentioned
The sender “signs” a message as:
Digital Signature
Artificial Signature
Encrypted Signature
In encryption:
Public key is used
Private key is used
Both public and private keys are used
AES stands for:
Advanced Encryption Standard
Advanced Encryption System
Advanced Encryption Suggestion
Authentication is:
Verification of user’s identification
Verification of the data
All answers are correct
No correct answer
The process to discover plaintext or key is known as
Cryptanalysis
Crypto design
Crypto processing
Cryptology
Output message in cryptography is called:
Ciphertext
Raw text
Input message in cryptography is called:
Encrypted text
In cryptography
Information is transmitted from sender to receiver
No information is transmitted
Information is damaged
Secure hash algorithm(SHA) developed by:
National Institute of Standards and Technology (NIST) or NSA
IEEE
ANSI
Conventional encryption is:
Symmetric encryption
Secret key encryption
Single key encryption
In network security:
Data is protected from hackers
Data is protected from cracker
Both answers are possible
DSS stands for:
Digital signature standard
Digital sound system
Digital simulation schemes
None of these
Cryptography ensures:
Confidentiality of data
Authentication of data
Integrity of data
Data is protected during transmission
Data is not protected during transmission
Data is changed
Network security ensures:
Detecting attacks
Preventing attacks
Recovering attacks
Encryption protects against:
Attacks
Viruses
Manipulation of data
Authentication refers to:
Verification of user’s identity
Checking user’s privileges
Auditing user’s process
The message is decrypted at ________ - side
Receiver
Sender
Broker
Attacker
Cryptography relates to ______
Editing
Security
Testing
Which of the following is not used for symmetric encryption?
SHAI
RC4
MD5
Finding plaintext, without knowing key is know as:
Which of the following is a transposition cipher?
Caesar cipher
Vigenere cipher
One time pad
Playfair cipher
Which of the following is a monoalphabetic cipher?
Caesar Cipher
Lucifier cipher
RSA involves very large _____ numbers.
Prime
Even
Odd
Any random
Cryptology means
Cryptography + Cryptodesign
Cryptography + Cryptanalysis
Cryptography itself known as cryptology also
Diffie-Hellman key exchange is vulnerable to:
Discrete logarithmic problem
Elliptic curve cryptography
Man-in-the-middle attack
None of these Which of the following is an example of a passive attack?
Modify
Denial of Service (DoS)
Masquerade
Traffic analysis
Which kind of service ensures that a message was received from the actual sender not from an attacker?
Access Control
Non-repudiation
Which of the following is an active attack? I. Release of message contents; II. Traffic analysis; III. Modify; IV. Denial of Service
I and II
I and III
III and IV
II and IV
I, III and IV
The method of hiding the secret is called
Watermarking
Steganography
It is the art of breaking the cipher
The field which deals with _____ called cryptography
Encryption techniques and secure systems
Firewalls, Kerberos and Intrusion detection systems
Operating systems
What would be the number of rounds in AES, if the key size is 24 bytes?
10
26
What would be the number of rounds in AES, if the key size is 32 bytes?
Which of the following step is absent in the last round of AES?
Shift row
Mix columns
Byte substitution
Add subkey
DES algorithm uses total ______ subkeys
24
The total number of rounds in DES algorithm.
Which of the following method provides a one-time session key for two parties?
What is the size of round key for DES algorithm?
128-bit
What is the purpose of access control list?
to enforce a specified security policy
to prevent unauthorised access to data
to emphasize encryption
it is a key distribution center
Define a subject of Access Control List
an active entity requesting for resource access
a passive entity and target of the protection
an access control decision function
an access control information function
Define an object of Access Control List
What does multilevel security mean?
Classification of information by the level of importance and permission of access by users with different security clearance
Classification of information by date and permission of access by users with different security clearance
Classification of information by the level of importance and permission of access by users name
Classification of information by date and permission of access by users name
How many levels are covered in multilevel security
1
2
3
4
No read up (read down) means
A subject can only read an object of less or equal security level
A subject can only write into an object of greater or equal security level
A subject can only read an object of more or equal security level
A subject can only write into an object of less or equal security level
No write down (write up) means
What does “computationally infeasible to find data mapping to specific hash” mean?
One way property
Collision free property
Second way property
Collision property
Which of the following is not property of hash functions?
One wayness
Preimage resistance
Strong collision resistance
Long, unfixed output
The purpose of hash function is to
Create a message
Compress a message
Divide a message
Conquer a message
Which of the following refers requirement of digital signature?
Must be relatively hard to produce
Must be relatively hard to recognize
Must depend on the message verified
Must to be computationally infeasible to forge
Must to be practical to save digital signature in storage
What is the property of direct digital signature?
Assumed receiver has sender’s private key
Involves only sender
Can encrypt using receiver’s public key
Assumed sender has receiver’s private key
Define AAA.
Access After Anyone
Authentication Authorization Accounting
Authentication Authorization Access
Authentication Access Accounting
Which of the term refers to authorization?
The user identity is a parameter in access control decisions
The user identity is recorded when logging security
The process of verifying a claimed identity
Accounting of service
Which of the term refers to accounting?
Define X.509
TTP certifies trustworthiness of binding public key with its rightful owner’s identity
TTP certifies trustworthiness of binding private key with its rightful owner’s identity
To enable the validation and to give legal meaning to digital signature
Answers for supporting encryption/decryption algorithms
Define a Kerberos
Trusted third party authentication system and makes no use of public key cryptography
Which of the following does not refer for Kerberos property
Impeccability
Containment
Transparency
Viciousness
How BruteForce works
аttаckеr triеs еvеry possiblе combinаtion of chаrаctеrs
Install viruses
Attacker sends more data to an application than is expected
Attacker knows of a security problem within an operating system or a piece of software and leverages that knowledge by exploiting the vulnerability