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This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Communications knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which should be used first to decrypt? |
A. | Public key |
B. | Private key |
C. | Public & Private key |
D. | None of the mentioned |
Answer» C. Public & Private key | |
2. |
Which algorithm is used for public key encryption? |
A. | RSA |
B. | Diffie-Hellman |
C. | RSA & Diffie-Hellman |
D. | None of the mentioned |
Answer» D. None of the mentioned | |
3. |
WHAT_IS_THE_KEY_SIZE_ALLOWED_IN_PGP??$ |
A. | 1024-1056 |
B. | 1024-4056 |
C. | 1024-4096 |
D. | 1024-2048 |
Answer» D. 1024-2048 | |
4. |
Which should be used first to decrypt?$ |
A. | Public key |
B. | Private key |
C. | Public & Private key |
D. | None of the mentioned |
Answer» C. Public & Private key | |
5. |
Which algorithm is used for public key encryption?$ |
A. | RSA |
B. | Diffie-Hellman |
C. | RSA & Diffie-Hellman |
D. | None of the mentioned |
Answer» D. None of the mentioned | |
6. |
DSA protocol is based on |
A. | Discrete logarithm problem |
B. | Continuous logarithm problem |
C. | Discrete & Continuous logarithm problem |
D. | None of the mentioned |
Answer» B. Continuous logarithm problem | |
7. |
The hash function |
A. | Is collision free |
B. | Has manageable collision |
C. | Has high unmanageable level of collision |
D. | None of the mentioned |
Answer» B. Has manageable collision | |
8. |
In hash function output length is fixed. |
A. | True |
B. | False |
Answer» B. False | |
9. |
The digital signature provides authentication to the |
A. | Sender |
B. | Message |
C. | Sender & Message |
D. | None of the mentioned |
Answer» D. None of the mentioned | |
10. |
Which operation is used in encryption using IDEA? |
A. | Addition modulo 216 |
B. | Bit wise XOR |
C. | Addition modulo 216 & Bit wise XOR |
D. | None of the mentioned |
Answer» D. None of the mentioned | |
11. |
The key size of DES is |
A. | 56 bits |
B. | 64 bits |
C. | 128 bits |
D. | 168 bits |
Answer» B. 64 bits | |
12. |
These three ciphers can operate of ______ of plaintext and cipher text. |
A. | 128 bit blocks |
B. | 64 bit blocks |
C. | 256 bit blocks |
D. | 156 bit blocks |
Answer» C. 256 bit blocks | |
13. |
Which block cipher has key length of 128 bits? |
A. | IDEA |
B. | CAST |
C. | IDEA & CAST |
D. | None of the mentioned |
Answer» D. None of the mentioned | |
14. |
PGP offers _____ block ciphers for message encryption. |
A. | Triple-DES |
B. | CAST |
C. | IDEA |
D. | All of the mentioned |
Answer» E. | |
15. |
Data compression includes |
A. | Removal of redundant character |
B. | Uniform distribution of characters |
C. | Removal of redundant character & Uniform distribution of characters |
D. | None of the mentioned |
Answer» D. None of the mentioned | |
16. |
For digital signatures private key cryptosystem is used. |
A. | True |
B. | False |
Answer» C. | |
17. |
Public key cryptosystem is used for the encryption of |
A. | Messages |
B. | Session key |
C. | Session key & Messages |
D. | None of the mentioned |
Answer» C. Session key & Messages | |
18. |
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 |
Answer» D. None of the mentioned | |