Paper 4 , Section I, 3K3 K

Coding and Cryptography
Part II, 2021

Describe the Rabin scheme for coding a message xx as x2x^{2} modulo a certain integer NN.

Describe the RSA encryption scheme with public key (N,e)(N, e) and private key dd.

[In both cases you should explain how you encrypt and decrypt.]

Give an advantage and a disadvantage that the Rabin scheme has over the RSA scheme.