  In modern age, the increasing complexity of computation and communication
technology is leading us towards the necessity of new paradigm. As a result,
unconventional approach like DNA coding theory is gaining considerable
attention. The storage capacity, information processing and transmission
properties of DNA molecules stimulate the notion of DNA coding theory as well
as DNA cryptography. In this paper we generate DNA codeword using DNA linear
block codes which ensures the secure transmission of information. In the
proposed code design strategy DNA-based XOR operation (DNAX) is applied for
effective construction of DNA codewords which are quadruples generated over the
set of alphabets consisting of four DNA bases adenine, thymine, guanine, and
cytosine. By worked out examples we explain the use of generator matrix and
parity check matrix in encryption and decryption of coded data in the form of
short single stranded DNA sequences. The newly developed technique can detect
as well as correcting error in transmission of DNA codewords through biological
channels from sender to the intended receiver. Through DNA coding theory we are
expanding the paths towards data compression and error correction in the form
of DNA strands. This leads us towards a broader domain of DNA cryptography.
