MCQOPTIONS
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MCQOPTIONS
This section includes 16 Mcqs, each offering curated multiple-choice questions to sharpen your Cryptography and Network Security knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Consider the cipher text message with relative frequencies:4 0 10 25 5 32 24 15 6 11 5 5 1 2 6 6 15 19 10 0 6 28 8 2 3 2The Index of Coincidence is |
| A. | 0.065 |
| B. | 0.048 |
| C. | 0.067 |
| D. | 0.042 |
| Answer» D. 0.042 | |
| 2. |
Euler’s totient function is determined by |
| A. | pq |
| B. | (p-1)(q-1) |
| C. | (p+1)(q+1) |
| D. | p/q |
| Answer» C. (p+1)(q+1) | |
| 3. |
If all letters have the same chance of being chosen, the IC is approximately |
| A. | 0.065 |
| B. | 0.035 |
| C. | 0.048 |
| D. | 0.038 |
| Answer» E. | |
| 4. |
On Encrypting “thepepsiisintherefrigerator” using Vignere Cipher System using the keyword “HUMOR” we get cipher text- |
| A. | abqdnwewuwjphfvrrtrfznsdokvl |
| B. | abqdvmwuwjphfvvyyrfznydokvl |
| C. | tbqyrvmwuwjphfvvyyrfznydokvl |
| D. | baiuvmwuwjphfoeiyrfznydokvl |
| Answer» C. tbqyrvmwuwjphfvvyyrfznydokvl | |
| 5. |
Consider the cipher text message:YJIHX RVHKK KSKHK IQQEV IFLRK QUZVA EVFYZ RVFBX UKGBP KYVVB QTAJK TGBQO ISGHU CWIKX QUXIH DUGIU LMWKG CHXJV WEKIH HEHGR EXXSF DMIIL UPSLW UPSLW AJKTR WTOWP IVXBW NPTGW EKBYU SBQWSRelative Frequencies –3 7 2 2 5 5 7 9 11 4 14 4 2 1 3 4 6 5 6 5 7 10 9 8 4 2The Index of Coincidence is – |
| A. | 0.065 |
| B. | 0.048 |
| C. | 0.067 |
| D. | 0.044 |
| Answer» E. | |
| 6. |
A symmetric cipher system has an IC of 0.041. What is the length of the key ‘m’? |
| A. | 1 |
| B. | 3 |
| C. | 2 |
| D. | 5 |
| Answer» E. | |
| 7. |
In Merkle Hellman method same key is used for encryption and decryption. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 8. |
Use Caesar’s Cipher to decipher the following:HQFUBSWHG WHAW |
| A. | ABANDONED LOCK |
| B. | ENCRYPTED TEXT |
| C. | ABANDONED TEXT |
| D. | ENCRYPTED LOCK |
| Answer» C. ABANDONED TEXT | |
| 9. |
On Encrypting “cryptography” using Vignere Cipher System using the keyword “LUCKY” we get cipher text |
| A. | nlazeiibljji |
| B. | nlazeiibljii |
| C. | olaaeiibljki |
| D. | mlaaeiibljki |
| Answer» B. nlazeiibljii | |
| 10. |
The Index of Coincidence for English language is approximately |
| A. | 0.068 |
| B. | 0.038 |
| C. | 0.065 |
| D. | 0.048 |
| Answer» D. 0.048 | |
| 11. |
In base 26, multiplication of YES by NO gives – |
| A. | THWOE |
| B. | MPAHT |
| C. | MPJNS |
| D. | THWAE |
| Answer» D. THWAE | |
| 12. |
Division of (131B6C3) base 16 by (lA2F) base 16 yeilds – |
| A. | 1AD |
| B. | DAD |
| C. | BAD |
| D. | 9AD |
| Answer» E. | |
| 13. |
An encryption scheme is unconditionally secure if the ciphertext generated does not contain enough information to determine uniquely the corresponding plaintext, no matter how much cipher text is available. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 14. |
Divide (HAPPY)26 by (SAD)26. We get quotient – |
| A. | KD |
| B. | LD |
| C. | JC |
| D. | MC |
| Answer» B. LD | |
| 15. |
Dividing (11001001) by (100111) gives remainder – |
| A. | 11 |
| B. | 111 |
| C. | 101 |
| D. | 110 |
| Answer» E. | |
| 16. |
The estimated computations required to crack a password of 6 characters from the 26 letter alphabet is- |
| A. | 308915776 |
| B. | 11881376 |
| C. | 456976 |
| D. | 8031810176 |
| Answer» B. 11881376 | |