Suppose Bob uses text-book RSA (without padding and without random-ization) public-key crypto-system with modulusn. Bob’s public key is(n, e) and his private key is (n, d).Suppose Alice sends an English-languagemessage by representing each alphabetic character as an integer between0 and 25 (i. e.,Ais represented as 0,Bis represented as 1 and so on), andthen encrypting each (representation of) character of the plaintext withthe same key.•Describe a COA attack on this encryption scheme, that is describehow an eavesdropper Charlie, who sees the cipher-text can decryptit if a long enough message was sent.•Does RSA-OAEP prevent this attack (give reasons for your answer)?