GATE CSE 2007 | Network Security Question 12 | Computer Networks

GATE CSE 2007

MCQ (Single Correct Answer)

-0.3

Consider the following two statements:

i. A hash function (these are often used for computing digital signatures) is an injective function.
ii. encryption technique such as DES performs a permutation on the elements of its input alphabet.

Which one of the following options is valid for the above two statements?

Both are false

Statement (i) is true and the other is false

Statement (ii) is true and the other is false

Both are true

GATE CSE 2007

MCQ (Single Correct Answer)

-0.3

The minimum positive integer p such that (3^p modulo 17) = 1 is

GATE CSE 2007

MCQ (Single Correct Answer)

-0.3

Exponentiation is a heavily used operation in public key cryptography. Which of the following options is the tightest upper bound on the number of multiplications required to compute (bⁿ mod m),$$0 \le b,n \le m$$?

$${\rm O}\left( {\log n} \right)$$

$${\rm O}\left( {\sqrt n } \right)$$

$${\rm O}\left( {{n \over {\log n}}} \right)$$

$${\rm O}\left( n \right)$$

GATE CSE 2004

MCQ (Single Correct Answer)

-0.3

A sender is employing public key Cryptography to send a secret message to a receiver. Which one of the following statement is true?

Sender encrypts using receiver's public key.

Sender encrypts using his own public key.

Receiver decrypts using sender's public key.

Receiver decrypts using his own public key.