Deck 4: Cryptography and Encryption Techniques

Question 1

Till when was the RC4 algorithm kept a secret?

A)1990
B)1992
C)1996
D)1994

Answer 1

1994

Question 2

The Plaintext for the Ciphertext 00100010, given that the key is 1111111111 is

A)1100111
B)1010
C)1001000
D)1001100

Answer 2

1001100

Question 3

The man-in-the-middle attack can endanger the security of the Diffie-Hellman method if two parties are not

A)authenticated
B)joined
C)submit
D)separate

Answer 3

authenticated

Question 4

RSA is also a stream cipher like Merkel-Hellman

Question 5

Rabin Cryptosystem is a variant of the Elgamal Cryptosystem

Question 6

In RSA, ?(n) = in terms of p and q

A)(p)/(q)
B)(p)(q)
C)(p-1)(q-1)
D)(p+1)(q+1)

Question 7

In Asymmetric Key Cryptography, the two key, e and d, have a special relationship to

A)others
B)data
C)keys
D)each other

Question 8

Using Rabin cryptosystem with p=23 and q=7 ,Encrypt P=24 to find ciphertext. The Cipher text is

A)42
B)93
C)74
D)12

Question 9

For RSA to work, the value of P must be less than the value of

A)p
B)q
C)n
D)f

Question 10

Session keys are transmitted after being encrypted by

A)make-shift keys
B)temporary keys
C)master keys
D)section

Question 11

Which Cryptographic system uses C1 = (e1r) mod p and C1 = (e2r x P) mod p at the encryption side?

A)elgamal
B)rsa
C)rabin
D)whirlpool

Question 12

The certificate message is required for any agreed-on key exchange method except

A)ephemeral diffie- hellman
B)anonymous diffie- hellmanc
C)fixed diffie- hellmand.
D)rsa

Question 13

Sender chooses p = 107, e1 = 2, d = 67, and the random integer is r=45. Find the plaintext to be transmitted if the ciphertext is (28,9)

A)45
B)76
C)66
D)13

Question 14

In Asymmetric key Cryptography, although RSA can be used to encrypt and decrypt actual messages, it is very slow if the message is

A)short
B)long
C)flat
D)thin

Question 15

Which of the following is not a type of symmetric-key cryptography technique?

A)caesar cipher
B)data encryption standard (des)
C)diffie hellman cipher
D)playfair cipher

Question 16

In Elgamal cryptosystem, given the prime p=31,Choose e1= first primitive root of p and d=10, calculate e2

A)24
B)36
C)25
D)62

Question 17

How many bytes of the secret key is generated using Diffie-Hellman encryption/decryption scheme?

A)256
B)871
C)1024
D)962

Question 18

Computation of the discrete logarithm is the basis of the cryptographic system

A)symmetric cryptography
B)asymmetric cryptography
C)diffie-hellman key exchange
D)secret key cryptography

Question 19

In Elgamal cryptosystem, given the prime p=31,Encrypt the message "HELLO"; use 00 to 25 for encoding. The value of C2 for character 'O' is

A)9
B)7
C)23
D)27

Question 20

What is the block size of RC6 Feistel block cipher?

A)5013 bits
B)128 bits
C)596 bits
D)1768 bits

Question 21

What is the general equation for elliptic curve systems

A)y3+b_1 xy+b_2 y=x33+a_1 x2+a_2 x+a_3
B)y3+b_1 x+b_2 y=x2+a_1 x2+a_2 x+a_3
C)y2+b_1 xy+b_2 y=x3+a_1 x2+a_2
D)y2+b_1 xy+b_2 y=x3+a_1 x2+a_2 x+a_3

Question 22

USENET falls under which category of public key sharing?

A)public announcement
B)publicly available directory
C)public-key authority
D)public-key certificates

Question 23

In Singular elliptic curve, the equation x^3+ax+b=0 does_______roots

A)does not have three distinct
B)has three distinct
C)has three unique
D)has three distinct unique

Question 24

The value of 52003 mod 7 is(use fermat's theorem)

A)3
B)4
C)8
D)9

Question 25

Elliptic curve cryptography follows the associative property