Home
Courses
About
School
Notes
Questions
MCQ
Contact
Vocational Courses
Digital Communications
Digital Communications
Public Key Cryptosystems
Question 1
Marks :
+2
|
-2
Pass Ratio :
100%
In cipher feedback method, encryption is done on
Single individual bits
Characters
Single individual bits & Characters
None of the mentioned
Explanation:
In cipher feedback method, single individual bits are encrypted rather than characters and this leads to stream encryption.
Question 2
Marks :
+2
|
-2
Pass Ratio :
100%
Which algorithm can be used to sign a message?
Public key algorithm
Private key algorithm
Public & Private key algorithm
None of the mentioned
Explanation:
Public key algorithms are used to sign a message and private key algorithms are used to encrypt the messages.
Question 3
Marks :
+2
|
-2
Pass Ratio :
100%
Public key cryptosystem uses same key for both encryption and decryption.
True
False
Explanation:
Public key cryptosystem uses different keys for encryption and decryption.
Question 4
Marks :
+2
|
-2
Pass Ratio :
100%
Encryption transformations are known as
Diffusion
Confusion
Diffusion & Confusion
None of the mentioned
Explanation:
The encryption transformations were termed confusion and diffusion by Shannon.
Question 5
Marks :
+2
|
-2
Pass Ratio :
100%
In a trapdoor function, the functions are easy to go in
One direction
Two directions
All directions
None of the mentioned
Explanation:
A trapdoor is a one way function. Such functions can go easily in only one direction.
Question 6
Marks :
+2
|
-2
Pass Ratio :
100%
In public key cryptosystem which is kept as public?
Encryption keys
Decryption keys
Encryption & Decryption keys
None of the mentioned
Explanation:
In public key cryptosystem, the encryption keys are kept as public where as decryption keys are kept as secret.
Question 7
Marks :
+2
|
-2
Pass Ratio :
100%
Pretty good privacy program is used for
Electronic mails
File encryption
Electronic mails & File encryption
None of the mentioned
Explanation:
Pretty good privacy (PGP) privacy program is used for both electronic mails and file encryption.
Question 8
Marks :
+2
|
-2
Pass Ratio :
100%
In which method, key-stream is generated independently?
Synchronous
Self synchronous
Synchronous & Self synchronous
None of the mentioned
Explanation:
In synchronous encryption system, the key-stream is generated independently of the message.
Question 9
Marks :
+2
|
-2
Pass Ratio :
100%
Cipher system can be solved effectively by statistically using
Time of occurrence
Frequency of occurrence
Length of the message
None of the mentioned
Explanation:
By statistically using the frequency of occurrence of individual characters and character combinations we can solve many cipher systems.
Question 10
Marks :
+2
|
-2
Pass Ratio :
100%
In transposition, the plaintext letters are
Substituted
Rearranged
Removed
None of the mentioned
Explanation:
In permutation or transposition, the positions of the plaintext letters in the message are simply rearranged.
1
2
3
4
5
6
7
8
9
10
Time Left:
Submit
Score
:
Rank
:
Accuracy
:
%
Time
:
Total Question
:
Attempted
:
Correct
:
Wrong
:
User Name
Email Id
Mobile No
Submit