Using:

Encryption fuction is E(x)=x^e modm

Then finding the decryption function

D(x)=x^d modm

Then compute d such that ed=1modphi(m)

1. (Credit Card number) Suppose you have a credit card with number 1035 2264 0960 1395 and you want to purchase something online with it. The website you are buying has RSA public key m 2701 and e 47 (a) What is your encrypted credit card number your computer sends to this website provided you encrypt 4 digits at a time? (b) It turns out that your credit card number above is really a secret question for you, en crypted by the RSA public key m 2701 and e 47. Find the secret decryption key od, decode the question and answer t. The convention for converting to letters is as in class: A01, B-02,... ,Z-26