This paper presents the possibilities of combing public-key encryption and digital signature algorithms which are actually based on different mathematical hard problems. Since the output of the combination produces an Encrypted signed message. In general, most of the currently used public-key algorithms are computationally expensive with relatively lengthy key requirement due to the dependency on the number theory. Therefore, it's important to show a combinational protocols which are based on different mathematical hard problem. In some sense, difficult to solve. In the combined scheme, we present the powerful and practical encryption digital signature scheme and its security level and execution time.