Assume that there is a block cipher ABC that always encrypts block of b=72 bits using key of k= 60 bits. We know that ABC will be broken even using simple brute-force attacking by guessing the encryption key. To enhance the security level, assume that someone proposes to use XYZ by use of 2 encryptions of ABC with 2 different independent keys. Prove that XYZ does not provide a much stronger security than ABC. Prove in detail why this statement is true. (You have to analyze in detail a method attacking XYZ using time that is not much longer than the brute force attacking on ABC.)