  Security of information has become a major issue during the last decades. New
algorithms based on chaotic maps were suggested for protection of different
types of multimedia data, especially digital images and videos in this period.
However, many of them fundamentally were flawed by a lack of robustness and
security. For getting higher security and higher complexity, in the current
paper, we introduce a new kind of symmetric key block cipher algorithm that is
based on \emph{tripled chaotic maps}. In this algorithm, the utilization of two
coupling parameters, as well as the increased complexity of the cryptosystem,
make a contribution to the development of cryptosystem with higher security. In
order to increase the security of the proposed algorithm, the size of key space
and the computational complexity of the coupling parameters should be increased
as well. Both the theoretical and experimental results state that the proposed
algorithm has many capabilities such as acceptable speed and complexity in the
algorithm due to the existence of two coupling parameter and high security.
Note that the ciphertext has a flat distribution and has the same size as the
plaintext. Therefore, it is suitable for practical use in secure
communications.
