Suppose I have an arbitrary 256 bit number **m** another secret number **k** of the same bit length, and then I multiply them both modulo a 256 bit prime number **p** to get **c** as follows: ` c = (m*k) mod p ` Is there any way to get **m** back without knowing **k** ? Is this problem as hard as the descrete log problem? How can this task be made more computationally difficult?