Using RSA Encryption and the values for p=3, q=7 use the steps from the videos and PDF to calculate values for e and d
Also look at the videos in this module which give you another example of how to use RSA Encryption
show how to encrypt the letter ‘C’ and then decrypt back to ‘C’.
RSA Algorithm
Step 1 : Choose two prime numbers p and q. – You are given p=3 and q=7
Step 2 : Calculate n = p*q
Step 3 : Calculate ϕ(n) = (p – 1) * (q – 1)
Step 4 : Choose e such that e is coprime (do not have a common factor) with both n and ϕ(n)
Step 5 : Calculate d such that (d * e) mod ϕ(n) = 1
Step 6 : Public Key {e,n}
This will be a handy guide.
Step 7: Private Key {d,n}
Step 8 : Cipher text C = P^e mod n where P = plaintext
Step 9 : For Decryption D = C^d mod n where D will give back the plaintext.
