35. Which of these is not considered as a symmetric-key algorithm?

A. RSA

B. Caesar cipher

C. Vigenere Cipher

D. Playfair cipher

E. Hill Cipher

36. Which of the following statement(s) is(are) properties of public-key encryption?

A. One of the

two keys must be kept secret.

B. The same algorithm with the same key is used for encryption and decryption.

C. One algorithm is used for encryption and decryption with a pair of keys, one for encryption and one for decryption.

D. The sender and receiver must share the algorithm and the key.

E. The sender and receiver must each have one of the matched pair of keys(not the same one).

37. The process of verifying and identity claimed by or for a system entity.

A. Authentication

B. Confirmation

C. Processing

D. Timestamping

E. Validation

38. One of the two keys used in an asymmetric encryption system. For secure communication, the private key should only be known to its creator.

39. One of the two keys used in an asymmetric encryption system. The public key is made public to be used in conjunction with a corresponding private key.

40. A public-key encryption algorithm based on exponentiation in modular arithmetic. It is the only algorithm generally accepted as practical and secure for public-key encryption

A. RSA

B. Hill Cipher

C. Caesar Cipher

D. Vigenere Cipher

E. Playfair Cipher

41. Code embedded within a program that causes a copy of itself to be inserted in one or more other programs. Usually performs some unwanted function.

A. Virus

B. Worm

C. Zombie

D. Firewall

E. All of the statements

42. A process of identifying, analyzing and controlling critical information.

A. DMZ

B. OPSEC

C. Scanning

D. Firewall

E. Anti-virus

43. Embedded in a computer program that checks for a certain set of conditions to be present on the system. When these conditions are met, it executes some function resulting in unauthorized actions.

A. OPSEC

B. Virus

C. Logic Bomb

D. Worm

E. Trojan Horse

44. Secret undocumented entry point into a program, used to grant access without normal methods of access authentication.

A. Virus

B. Trapdoor

C. Worm

D. Logic Bomb

E. Trojan Horse

45. A computer program that appears to have a useful function, but also has a hidden and potentially malicious function that evades security mechanisms, sometimes by exploiting legitimate authorizations of a system entity that invokes the program

A. Logic Bomb

B. Virus

C. Worm

D. OPSEC

E. Trojan Horse

46. Program that can replicate itself and send copies from computer to computer across network connections. Usually performs some unwanted function.

A. Worm

B. Virus

C. Trojan Horse

D. OPSEC

E. Logical Bomb

47. A program that secretly takes over another Internet-attached computer and then uses that computer to launch attacks that are difficult to trace to the creator.

A. Zombie

B. Worm

C. Virus

D. Logical Bomb

E. OPSEC

48. In a public-key system using RSA, you intercept the ciphertext C = 10 sent to a user whose public key is e = 5, n = 35. What is the φ(n)? 24

49. Encrypt the message "HELLO" using the Hill cipher with the key. Take the indices of letters according to the given table. BLNCKX

50. In a public-key system using RSA, you intercept the plaintext M = 13 sent to a user whose public key is e = 5, n = 35. What will be the ciphertext C? 13

51. Decipher the message YITJPG using the Hill cipher with the inverse key Take the indices of letters according to the given table. DIFFIC

52. In an RSA system, the public key of a given user is e = 31, n = 3599. What is the φ(n)? 3480

53. Which of the statement(s) is(are) properties for p and q?

A. p and q are distinct

B. p and q are prime

C. p and q should be of similar bit length

D. p is greater than q

E. p = q -1

54. Which one of the statement is a formula to find cipher in RSA?

A. <i>c</i> = <i>m<i/> ^e (mod <i>n</i>).

B. <i>c</i> = <i>m<i/> ^d (mod <i>n</i>).

C. <i>c</i> = <i>m<i/> ⁿ (mod <i>e</i>).

D. <i>c</i> = <i>m<i/> ⁿ (mod <i>d</i>).

E. <i>c</i> = <i>m<i/> ^e (mod <i>d</i>).

55. Which one of the statement is a formula to find plain in RSA?

A. <i>m</i> = <i>c<i/> ^e (mod <i>n</i>).

B. <i>m</i> = <i>c<i/> ^d (mod <i>n</i>).

C. <i>m</i> = <i>c<i/> ⁿ (mod <i>e</i>).

D. <i>m</i> = <i>c<i/> ⁿ (mod <i>d</i>).

E. <i>m</i> = <i>c<i/> ^e (mod <i>d</i>).

56. Which one of the statement is equation for φ(n)?

A. φ(n) = (p)(q – 1)

B. φ(n) = (p – 1)(q)

C. φ(n) = (p – q)(q – 1)

D. φ(n) = (p – 1)(q – 1)

E. φ(n) = pq

57. In a public-key system using RSA, you intercept the ciphertext C = 10 sent to a user whose public key is e = 5, n = 35. What is the value of p and q?

A. p = 6, q = 8

B. p = 1, q = 35

C. p = q = n = 35

D. p = 5, q = 7

E. p = q = e = 5

58. In an RSA system, the public key of a given user is e = 31, n = 3599. What is the value of p and q?

A. p = 61, q = 59

B. p = 62, q = 60

C. p = 1, q = 3599

D. p = q = n = 3599

E. p = q = e = 31