Computer network security, Question-23, GATE 2016 (set-2)

Anarkali digitally signs a message and sends it to Salim. Verification of the signature by Salim requires

(A) Anarkali’s public key.
(B) Salim’s public key.
(C) Salim’s private key.
(D) Anarkali’s private key.

Computer network security, Question 68, GATE IT 2008

The total number of keys required for a set of n individuals to be able to communicate with each other using secret key and public key crypto-systems, respectively are:

(A) n(n-1) and 2n
(B) 2n and ((n(n - 1))/2)
(C) ((n(n - 1))/2) and 2n
(D) ((n(n - 1))/2) and n

isro cs question paper solution 2018 Q74 Set-A

 Avalanche Effect in Cryptography

(a) Is desirable property of cryptographic algorithm
(b) Is undesirable property of cryptographic algorithm
(c) Has no effect on encryption algorithm.
(d) None of above

Correct Answer is: (a)
Avalanche effect is drastic change in the cipher-text with small changes( e.g. change of a bit from 0 to 1) in either plain-text or key used for encryption/hashing.

https://en.wikipedia.org/wiki/Avalanche_effect