In this paper, a blind crypto-stego technique is introduced using the cryptography and steganography concepts to achieve a double layered secured system. The proposed method consists of two phases: First is the data conversion to DNA using the proposed generic N-bits binary coding rule that leads to lower cracking probability proved by some comparative studies. Then, DNA and amino acids Playfair is applied to encrypt the DNA of the message resulting in ambiguity. In the second phase, the cipher text is placed with the ambiguity using 3:1 placement strategy. Then they are shuffled to be hidden in DNA at random positions generated by using a true real random number seed that is obtained from the atmospheric noise, thereby achieving very low cracking probability. The proposed technique is a blind preserved one as it achieves zero modification for the generated protein without extra data.