Network Security Quiz 1

1.Steganography hides secret message in other message.
Select one:
True {correct}
False

2.Each DES S-box has six input bits and four output bits.
Select one:
True  {correct}                      
False

3.According kerchoff's principle, a cryptosystem should be secure even if the attacker knows all details about the system, with the exception of the secret key.
Select one:
True {correct}
False

4.RC4 encrypts data byte by byte.
Select one:
True {correct}
False

5.In substitution cipher order of the letter does not change.
Select one:
True {correct}
False

6.According kerchoff's principle, the attacker should not know the encryption and decryption algorithms.
Select one:
True
False {correct}

7.A mono-alphabetic substitution cipher replaces one character with another character.
Select one:
True{correct}
False

8.In transposition cipher order of the letter does not change.
Select one:
True
False {correct}

9.DES is a cipher encrypts blocks of length of 64 bits with a key of size of 56 bits.
Select one:
True {correct}
False

10.Substitution cipher rearrange the order of the letters in a message.
Select one:
True
False {correct}

11.A cryptosystem is computationally secure if the best known algorithm for breaking it requires at least 't' operations.
Select one:
True{correct}
False

12.In a symmetric key cipher, the same key is used by both the sender and receiver.
Select one:
True{correct}
False

13.A cryptosystem is unconditionally secure if it cannot be broken even with infinite computational resources.
Select one:
True {correct}
False

14.Cryptography provides security through obscurity.
Select one:
True
False {correct}

15.In a symmetric key cipher, different key are used by both the sender and receiver.
Select one:
True
False {correct}

16.RC4 encrypts data bit by bit.
Select one:
True
False {correct}

17.Steganography provides security through obscurity.
Select one:
True{correct}
False

18.Range of possible values used to construct keys is called key space.
Select one:
True {correct}
False

19.The ciphertext is the message after transformation.
Select one:
True {correct}
False

20.There are 5 equivalence class for the modulus 5.
Select one:
True {correct}
False

21.Each DES S-box has four input bits and four output bits.
Select one:
True
False {correct}

22.Cryptanalysis is used to find some insecurity in a cryptographic scheme.
Select one:
True {correct}
False

23.DES is a cipher  encrypts blocks of length of 64 bits with a key of size of 48 bits.
Select one:
True
False {correct}


24.Transposition cipher rearrange the order of the letters in a message.
Select one:
True{correct}
False

25.There are 8 equivalence class for the modulus 7.
Select one:
True
False {correct}