The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
x
0 votes
65 views
Using RSA key crypto system with a = 1, b = 2 etc; value for encryption if prime value are p = 7 and q = 11, the legal value for secret key is .

a)69

b)49

c)49

d)119
asked in Computer Networks by (255 points) | 65 views
0
both c and b options are 49?
0

i think 49 will be the answer 

three condition should be follow to choose key

(1) n=p*q=7*11

n=77

(2) Euler  Totient  function $\phi(n)=(p-1)(q-1)${if p and q are prime numbers}

$\phi(n) =6*10=60$

(3) now choose e such that 1<e<$\phi(n) $ and e and $\phi(n) $ should be coprime 

means GCD(e,$\phi(n) $)=1 

by seeing option only 49 is satisfying the condition because 49 is less than 60 and also GCD(49,60)=1

then (e,n) will be used as public key which will be used to encrypt the message .

 

 

0

Prateek but u calculated e?

0
Yeah you are right ,I think question is about e otherwise i don't know what is mean by secret key

1 Answer

0 votes
i think ans will be 49
answered by (23 points)

Related questions



Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true

42,628 questions
48,620 answers
155,926 comments
63,878 users