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WorksheetsCS Quiz Test 2
Total questions: 25
Worksheet time: 13mins
In cryptography, what is cipher?
algorithm for performing encryption and decryption
encrypted message
both (a) and (b)
none of these
A(n) ______ algorithm transforms ciphertext to plaintext.
encryption
decryption
either (a) or (b)
neither (a) nor (b)
Cryptanalysis is used
A.) to find some insecurity in a cryptographic scheme
B.) to increase the speed
C.) to encrypt the data
D.) none of these
Which one of the following algorithm is not used in asymmetric-key cryptography?
A.) RSA algorithm
B.) diffie-hellman algorithm
C.) electronic code book algorithm
D.) none of these
What is data encryption standard (DES)
A.) block cipher
B.) stream cipher
C.) bit cipher
D.) none of these
In asymmetric key cryptography, the private key is kept by
A.) sender
B.) receiver
C.) sender and receiver
D.) all the connected devices to the network
The ________ is the message after transformation.
A) ciphertext
B) plaintext
C) secret-text
D) none of the above
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.
A) S-box
B) P-box
C) T-box
D) none of the above
A ________ cipher replaces one character with another character.
A) substitution
B) transposition
C) either (a) or (b)
D) neither (a) nor (b)
The ________ cipher reorders the plaintext characters to create a ciphertext.
A) substitution
B) transposition
C) either (a) or (b)
D) neither (a) nor (b)
A combination of an encryption algorithm and a decryption algorithm is called a ________.
A) cipher
B) secret
C) key
D) none of the above
In an asymmetric-key cipher, the receiver uses the ______ key.
A) private
B) public
C) either a or b
D) neither (a) nor (b)
DES is a(n) ________ method adopted by the U.S. government.
A) symmetric-key
B) asymmetric-key
C) either (a) or (b)
D) D) neither (a) nor (b)
DES uses a key generator to generate sixteen _______ round keys.
A) 32-bit
B) 48-bit
C) 54-bit
D) 42-bit
The Caesar cipher is a _______cipher that has a key of 3.
A) transposition
B) additive
C) shift
D) none of the above
ECB and CBC are ________ ciphers.
A) block
B) stream
C) field
D) none of the above
________ is the science and art of transforming messages to make them secure and immune to attacks.
A) Cryptography
B) Cryptoanalysis
C) either (a) or (b)
D) neither (a) nor (b)
DES has an initial and final permutation block and _________ rounds.
A) 14
B) 15
C) 16
D) none of the above
_________ ciphers can be categorized into two broad categories: monoalphabetic and polyalphabetic.
A) Substitution
B) Transposition
C) either (a) or (b)
D) neither (a) nor (b)
There are _______ major ways of stealing email information.
2
3
4
5
Which of them is not a proper method for email security?
a) Use Strong password
b) Use email Encryption
c) Spam filters and malware scanners
d) Click on unknown links to explore
Pretty good privacy (PGP) security system uses
a) Public key cryptosystem
b) Private key cryptosystem
c) Public & Private key cryptosystem
d) None of the mentioned
There are ________ major types of passwords
4
5
6
7
In _______________ attacks an attacker do not contact with authorizing party for stealing password.
a) passive online
b) active online
c) offline
d) non-electronic
The key size of DES is
a) 56 bits
b) 64 bits
c) 128 bits
d) 168 bits
