1. Another name for Message authentication codes is.
A. cryptographic codebreak.
B. cryptographic codesum.
C. cryptographic checksum.
D. cryptographic checkbreak.
Answer= cryptographic checksum
2. For a 150-bit message and a 10-bit MAC, how many values are the MAC value dependent on?.
A. 2140.
B. 2150.
C. 215.
D. 210.
Answer= 2140
3. Confidentiality can only be provided if we perform message encryption before the MAC generation..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= FALSE
4. MACs are also called.
A. testword.
B. checkword.
C. testbits.
D. none of the mentioned.
Answer= none of the mentioned
5. For a 100 bit key and a 32 bit tag, how many possible keys can be produced in the 3rd round?.
A. 24.
B. 232.
C. 216.
D. 264.
Answer= 24
6. MAC is a.
A. one-to-one mapping.
B. many-to-one mapping.
C. onto mapping.
D. none of the mentioned.
Answer= many-to-one mapping
7. For an n-bit tag and a k-bit key, the level of effort required for brute force attack on a MAC algorithm is.
A. 2k.
B. 2n.
C. min(2k,2n).
D. 2k/2n.
Answer= min(2k,2n)
8. Cryptographic hash functions execute faster in software than block ciphers..
A. Statement is correct.
B. Statement is incorrect.
C. Depends on the hash function.
D. Depends on the processor.
Answer= Depends on the processor
9. What is the value of ipad in the HMAC structure?.
A. 111110.
B. 110010.
C. 10110110.
D. 1110110.
Answer= 110010
10. What is the value of opad in the HMAC structure?.
A. 111110.
B. 110010.
C. 10110110.
D. 1011100.
Answer= 1011100
11. Data Authentication Algorithm (DAA) is based on.
A. DES.
B. AES.
C. MD-5.
D. SHA-1.
Answer= DES
12. Which mode of operation is used in the DAA?.
A. output feedback mode.
B. electronic code block mode.
C. cipher block chaining mode.
D. cipher feedback mode.
Answer= cipher block chaining mode
13. What is the full-form of CMAC?.
A. Code-based MAC.
B. Cipher-based MAC.
C. Construct-based MAC.
D. Collective-based MAC.
Answer= Cipher-based MAC
14. Which cryptographic algorithm is used in CMAC?.
A. Triple DES and AES.
B. DES.
C. RC-4.
D. AES.
Answer= Triple DES and AES
15. In CMAC, which scenario is a different key K2 is used instead of K1?.
A. If the tag is larger than the key length.
B. If the tag is shorter than the key length.
C. In the last step of the algorithm.
D. If the plaintext/message is not an integer multiple of the cipher clock length.
Answer= If the plaintext/message is not an integer multiple of the cipher clock length
16. K2 is derived by left shifting L by 2 bits. What is L defined as?.
A. E(K , 0b).
B. E(K , 10*b).
C. E(K , 1b).
D. E(K , 10*1b).
Answer= E(K , 0b)
17. Which Authentication Encryption approach is taken by the SSL/TLS protocol?.
A. Hashing followed by encryption (H?E).
B. Encryption followed by authentication (E?A).
C. Authentication followed by encryption (A?E).
D. Independently encrypt and authenticate (E + A).
Answer= Authentication followed by encryption (A?E)
18. Which Authentication Encryption approach is taken by the IPSec protocol?.
A. Authentication followed by encryption (A?E).
B. Hashing followed by encryption (H?E).
C. Encryption followed by authentication (E?A).
D. Independently encrypt and authenticate (E + A).
Answer= Encryption followed by authentication (E?A)
19. Which Authentication Encryption approach is taken by the SSH protocol?.
A. Hashing followed by encryption (H?E).
B. Encryption followed by authentication (E?A).
C. Authentication followed by encryption (A?E).
D. Independently encrypt and authenticate (E + A).
Answer= Independently encrypt and authenticate (E + A)
20. Hashing followed by encryption (H?E) is used by which algorithm?.
A. IPSec.
B. SSH.
C. WEP.
D. SSL/TLS.
Answer= WEP
21. Which of the following terms is not an input to the CCM encryption?.
A. Nonce..
B. Associated data..
C. Plaintext message..
D. Tag..
Answer= Tag.
22. How many passes through the plaintext does the CCM require to generate the MAC value?.
A. 2.
B. 3.
C. 4.
D. 5.
Answer= 2
23. When the length of the IV is not 96, then.
A. we append the rest of the bits with 1*0 to make it 128 bits.
B. we append the rest of the bits with 0*1 to make it 128 bits.
C. we append the rest of the bits with 1*0 to make it 256 bits.
D. we append the rest of the bits with 0s to make it 128 bits.
Answer= we append the rest of the bits with 0s to make it 128 bits
24. Which is not true for Key-Wrapping?.
A. Used for small Plain Texts.
B. It has a relatively higher throughput than other modes.
C. It has block size of 64 bits.
D. It has n+1 cipher blocks, for n plaintext block.
Answer= It has a relatively higher throughput than other modes
25. What is the value of A (0)?.
A. F9*.
B. A9*.
C. A6*.
D. F6*.
Answer= A6*
26. The cipher block is one block longer than the plaintext to accommodate the IV..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= TRUE
27. The key Wrapping Algorithm provides confidentiality and data integrity..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= TRUE
28. Which of the following is a valid disadvantage of the PRNG based on MAC function?.
A. It has a high throughput.
B. It takes twice the execution time.
C. It is hardware intensive and can only work on high end processors.
D. none of the mentioned.
Answer= It takes twice the execution time
29. Specify in the correct order (from top to bottom), which Pseudo Random Number Generation schemes are represented here?i)m = [ n/outlen]w_o = VW = the null stringFor i = 1 to mw_i = MAC(K,w_i-1)W = W || wiReturn leftmost n bits of Wii)m = [n/outlen]W = the null stringFor i = 1 to mw_i = MAC(K,V || i)W = W || w_iReturn leftmost n bits of Wiii)m = [n/outlen]A(0) = VW = the null stringFor I = 1 to mA(i) = MAC (K,A(i-1))w_i = MAC (K, a(I) || v)W = W || w_iReturn leftmost n bits of W.
A. NIST SP 800-90 ; TLS/WTLS ; IEEE 802.11.
B. TLS/WTLS ; NIST SP 800-90 ; IEEE 802.11.
C. IEEE 802.11 ; NIST SP 800-90 ; TLS/WTLS.
D. NIST SP 800-90 ; IEEE 802.11 ; TLS/WTLS.
Answer= NIST SP 800-90 ; IEEE 802.11 ; TLS/WTLS
30. Which of the following is not true for whirlpool hashing function?.
A. It is a two way hashing function.
B. It is based on a 512 bit block cipher.
C. The block cipher is similar to AES structure.
D. It is resistant to differential attacks.
Answer= It is a two way hashing function
31. The expected workload of generating a collision is of the order of ____________ executions of Whirlpool..
A. 2(n/2).
B. 2(n-1).
C. 2(n).
D. 2(2n).
Answer= 2(n/2)
32. Given a message, the expected workload of finding a message that hashes to that value is of the order ____________.
A. 2(n/2).
B. 2(n-1).
C. 2(n).
D. 2(2n).
Answer= 2(n)
33. Given a message and its n-bit hash result, the expected workload of finding a message that hashes to the same value is of the order _______________.
A. 2(n/2).
B. 2(n-1).
C. 2(n).
D. 2(2n).
Answer= 2(n)
34. The message is padded to.
A. 1024 bits.
B. 512 bits.
C. Odd multiple of 256 bits.
D. Odd multiple of 512 bits.
Answer= Odd multiple of 256 bits
35. The length of the message is appended to the message. What is the size of this length?.
A. 256 bits.
B. 512 bits.
C. 128 bits.
D. 1024 bits.
Answer= 256 bits
36. The hash matrix is of the size.
A. 16 × 8.
B. 16 × 4.
C. 8 × 8.
D. 4 × 16.
Answer= 8 × 8
37. The 8 × 8 hash matrix holds values of size.
A. 16 bits.
B. 32 bits.
C. 8 bits.
D. 4 bits.
Answer= 8 bits
38. The hash matrix of 8 × 8 is preferred over a 16 × 4 matrix because.
A. it is symmetric.
B. it is smaller in size.
C. it is faster in computation.
D. none of the mentioned.
Answer= it is faster in computation
39. How many rounds are there in one Whirlpool Iteration?.
A. 3.
B. 4.
C. 6.
D. 8.
Answer= 4
40. Which one of these is not a Whirlpool function?.
A. Add Key.
B. Substitute Bytes.
C. Mix Rows.
D. Shift Rows.
Answer= Shift Rows
41. What is the correct order of operation within each round of the Whirlpool algorithm?.
A. Add round key, Substitute bytes, Mix rows, Shift columns.
B. Substitute bytes, Add round key, Shift columns, Mix rows.
C. Mix rows, Substitute bytes, Shift columns, Add round key.
D. Substitute bytes, Shift columns, Mix rows, Add round key.
Answer= Substitute bytes, Shift columns, Mix rows, Add round key
42. What is the size of the s-box table/matrix in Whirlpool?.
A. 8 × 8.
B. 16 × 16.
C. 8 × 16.
D. 16 × 8.
Answer= 16 × 16
43. The S-box implements linear mapping thus providing diffusion..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= FALSE
44. Another name for the Whirlpool key is.
A. CState.
B. LState.
C. Estate.
D. KState.
Answer= KState
45. How many round constants (RCs) are required in Whirlpool?.
A. 10.
B. 11.
C. 12.
D. 21.
Answer= 10
46. The Round Constant is dependent on the s-box values..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= TRUE
47. The Round Constant is given by S[8(r-1)+j]. What are the limits of 'r'?.
A. 0 <= r <= 11.
B. 0 <= r <= 12.
C. 0 <= r <= 10.
D. 0 <= r <=16.
Answer= 0 <= r <= 10
48. When the Round Constant is given by S[8(r-1)+j]. What are the limits of 'i' and 'j'?.
A. i = 1 ; 0 <= j <= 7.
B. i = 0 ; 0 <= j <= 7.
C. 0 <= i <= 7; 0 <= j <= 7.
D. 0 <= i <= 7; j=0.
Answer= i = 0 ; 0 <= j <= 7
49. The 7th row in the 8 × 8 matrix undergoes a ___________ shift..
A. 6 bit.
B. 6 byte.
C. 7 bit.
D. 7 byte.
Answer= 6 byte
50. How many XOR gate operations are involved in the S-box permutation?.
A. 12.
B. 8.
C. 16.
D. 4.
Answer= 12
51. Which round provides linear diffusion in the Whirlpool Algorithm?.
A. Add Key.
B. Substitute Bytes.
C. Mix Rows.
D. Shift Rows.
Answer= Mix Rows
52. Mix Row functions operate on the 8 × 8 matrix (A) to form the new matrix. The operation can be considered to be B = AC. The matrix C is formed by.
A. each successive even row having left shifts.
B. each successive row having a left shifts.
C. each successive odd row having right shifts.
D. each successive row having a right shifts.
Answer= each successive row having a right shifts
53. Which of the following hexadecimal values are not present in the matrix C of the Mix Rows function?.
A. 1.
B. 9.
C. 5.
D. 3.
Answer= 3
54. There's no known successful attacks made against Whirlpool..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= TRUE
55. Which hash algorithm is the most hardware intensive among the following?.
A. SHA-1.
B. SHA-2.
C. MD-5.
D. Whirlpool.
Answer= Whirlpool
56. Which algorithm has the most execution latency?.
A. SHA-1.
B. SHA-2.
C. MD-5.
D. Whirlpool.
Answer= SHA-2
57. Which among the following has not been broken yet( still collision free)?.
A. MD-5.
B. SHA-1.
C. DES.
D. SHA-2.
Answer= SHA-2
58. Before the first round of the Whirlpool algorithm, which is the operation that takes place?.
A. Addition of Key.
B. Substitution of Bytes.
C. Mixing of Rows.
D. Shifting of Columns.
Answer= Addition of Key
59. How many rounds does the Whirlpool algorithm undergo?.
A. 12.
B. 14.
C. 10.
D. 16.
Answer= 10
60. Each round uses a different key in the algorithm..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= TRUE
61. What is the size of the key in the algorithm?.
A. 256 bits.
B. 512 bits.
C. 128 bits.
D. 1024 bits.
Answer= 512 bits
62. How many add round key functions are present in the Whirlpool algorithm?.
A. 16.
B. 18.
C. 11.
D. 10.
Answer= 11