This paper presents a new encryption and hiding algorithm based on a tribble selection from the open usable DNA sequences and elliptic curve cryptosystem with key size level between 160-bit and 512-bit. A set of three DNA reference sequences was randomly selected from NCBI database. Two DNA sequences were selected to work with a mathematical system, which consists of two distinct function to generate two keys. These keys were used to encrypt the message in the first encryption phase. Another encryption phase used the elliptic curve cryptosystem to run the second encryption on the message. Then, the message was hidden in the third DNA sequence. In addition, the paper describes a new encoding and decoding approach to convert between integer numbers and elliptic curve points. The proposed algorithm keeps the length of the DNA sequence unchanged. The simulation results showed the effectiveness of the proposed algorithm with respect to several parameters such as capacity(C), payload and bit per nucleotide (bpn).