MCQOPTIONS
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MCQOPTIONS
This section includes 11 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. |
Which attack requires the least effort/computations? |
| A. | Pre-image |
| B. | Second Pre-image |
| C. | Collision |
| D. | All required the same effort |
| Answer» D. All required the same effort | |
| 2. |
For an m bit hash value, if we pick data blocks at random we can expect to find two data blocks with the same hash value within ____ attempts. |
| A. | 2m |
| B. | 2(m-1) |
| C. | 2(m/2) |
| D. | (2m) – 1 |
| Answer» D. (2m) – 1 | |
| 3. |
For an m-bit value, the adversary would have to try ____________ values to generates a given hash value h. |
| A. | 2m |
| B. | 2(m-1) |
| C. | 2(m/2) |
| D. | (2m) – 1 |
| Answer» C. 2(m/2) | |
| 4. |
Consider the following propertiesVariable Input sizeFixed Output sizeEfficiencyPre image resistantSecond Pre image ResistantCollision resistantPseudo randomness A has function that satisfies the first _______ properties in the above table is referred to as a weak hash function. |
| A. | 5 |
| B. | 4 |
| C. | 3 |
| D. | 2View Answer |
| Answer» B. 4 | |
| 5. |
FOR_AN_M_BIT_HASH_VALUE,_IF_WE_PICK_DATA_BLOCKS_AT_RANDOM_WE_CAN_EXPECT_TO_FIND_TWO_DATA_BLOCKS_WITH_THE_SAME_HASH_VALUE_WITHIN______ATTEMPTS.?$ |
| A. | 2<sup>m</sup> |
| B. | 2<sup>(m-1)</sup> |
| C. | 2<sup>(m/2)</sup> |
| D. | (2<sup>m</sup>) – 1 |
| Answer» D. (2<sup>m</sup>) ‚Äö√Ñ√∂‚àö√ë‚àö¬® 1 | |
| 6. |
For an m-bit value, the adversary would have to try ____________ values to generates a given hash value h? |
| A. | 2<sup>m</sup> |
| B. | 2<sup>(m-1)</sup> |
| C. | 2<sup>(m/2)</sup> |
| D. | (2<sup>m</sup>) – 1 |
| Answer» D. (2<sup>m</sup>) ‚Äö√Ñ√∂‚àö√ë‚àö¬® 1 | |
| 7. |
A function that is second pre-image resistant is also collision resistant. |
| A. | True |
| B. | False |
| Answer» C. | |
| 8. |
The second pre-image resistant property is |
| A. | It is computationally infeasible to find any pair (x, y) such that H(x) = H(y) |
| B. | For any given block x, it is computationally infeasible to find y not equal to x, with H(y) = H(x) |
| C. | For any given hash value h it is computationally infeasible to find y such that H(y) = h |
| D. | None of the mentioned |
| Answer» C. For any given hash value h it is computationally infeasible to find y such that H(y) = h | |
| 9. |
We define collision as: A collision occurs if we have x=y and H(x) = H(y). |
| A. | True |
| B. | False |
| Answer» C. | |
| 10. |
What is the effectiveness of a 128 bit hash value? |
| A. | 2<sup>-64</sup> |
| B. | 2<sup>64</sup> |
| C. | 2<sup>-112</sup> |
| D. | 2<sup>-128</sup> |
| Answer» D. 2<sup>-128</sup> | |
| 11. |
What is the effectiveness of an n-bit hash value? |
| A. | 2<sup>n</sup> |
| B. | 2<sup>-n</sup> |
| C. | 2<sup>2n</sup> |
| D. | 2<sup>-2n</sup> |
| Answer» C. 2<sup>2n</sup> | |