To encrypt a plaintext M using an RSA public key we simply represent the plaintext as a number between 0 and N-1 and then compute the ciphertext C as: C = Me mod N.

Which is the formula used to generate ciphertext?

The conversion formula is of the form c ≡ p + a mod 26. We know that when p = 5 (plaintext E), we have c = 10 (ciphertext J). Thus, 10 ≡ 5 + a mod 26. So a ≡ 5 37 Page 4 mod 26, and the encryption formula is c ≡ p + 5 mod 26.

What is decryption algorithm formula in RSA?

RSA algorithm uses the following procedure to generate public and private keys: Select two large prime numbers, p and q. Multiply these numbers to find n = p x q, where n is called the modulus for encryption and decryption. If n = p x q, then the public key is <e, n>.