Computer Science Engineering (CSE) Exam  >  Computer Science Engineering (CSE) Questions  >  In a RSA cryptosystem a particular A uses two... Start Learning for Free
In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________. 

Note: This questions appeared as Numerical Answer Type.
  • a)
    11
  • b)
    13
  • c)
    16
  • d)
    17
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
In a RSA cryptosystem a particular A uses two prime numbers p = 13 and...
n an RSA cryptosystem, for public key: 
GCD( ϕ(n) , e) = 1 

And, for private key:
(e * d) mod ϕ(n) = 1 

Where, 
ϕ(n) = (p -1)*(q - 1) = (13 - 1)(17 - 1) =12*16 = 192 
Such that 1 < e, d < ϕ(n)

Therefore, the private key is:
(35 * d) mod ϕ(n) = 1
d = 11
View all questions of this test
Most Upvoted Answer
In a RSA cryptosystem a particular A uses two prime numbers p = 13 and...
Given:
In RSA cryptosystem, A uses two prime numbers p = 13 and q = 17 to generate her public and private keys. The public key of A is 35.

To find:
The private key of A.

Solution:

Step 1: Calculate n:
n = p * q
n = 13 * 17
n = 221

Step 2: Calculate phi(n):
phi(n) = (p - 1) * (q - 1)
phi(n) = (13 - 1) * (17 - 1)
phi(n) = 12 * 16
phi(n) = 192

Step 3: Find a number e such that 1 < e="" />< phi(n)="" and="" gcd(e,="" phi(n))="" />
Given, the public key of A is 35. Therefore, e = 35.

Step 4: Calculate d using the equation:
d * e ≡ 1 mod phi(n)

To calculate d, we need to find the modular multiplicative inverse of e with respect to phi(n).

Using Extended Euclidean Algorithm:
phi(n) = 192, e = 35

phi(n) = e * q + r
192 = 35 * 5 + 7

e = r * q1 + r1
35 = 7 * 5 + 0

The gcd of e and phi(n) is 1. So, d = q1 = 5.

Step 5: The private key of A is d = 5.

Therefore, the correct answer is option A) 5.
Explore Courses for Computer Science Engineering (CSE) exam

Top Courses for Computer Science Engineering (CSE)

In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer?
Question Description
In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? for Computer Science Engineering (CSE) 2024 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer?.
Solutions for In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Computer Science Engineering (CSE). Download more important topics, notes, lectures and mock test series for Computer Science Engineering (CSE) Exam by signing up for free.
Here you can find the meaning of In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer?, a detailed solution for In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of Ais 35. Then the private key of A is ____________.Note:This questions appeared as Numerical Answer Type.a)11b)13c)16d)17Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice Computer Science Engineering (CSE) tests.
Explore Courses for Computer Science Engineering (CSE) exam

Top Courses for Computer Science Engineering (CSE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev