  Recently, arithmetic coding has attracted the attention of many scholars
because of its high compression capability. Accordingly, in this paper a method
which adds secrecy to this well-known source code is proposed. Finite state
arithmetic code (FSAC) is used as source code to add security. Its finite state
machine (FSM) characteristic is exploited to insert some random jumps during
source coding process. In addition, a Huffman code is designed for each state
to make decoding possible even in jumps. Being Prefix free, Huffman codes are
useful in tracking correct states for an authorized user when s/he decodes with
correct symmetric pseudo random key. The robustness of our proposed scheme is
further reinforced by adding another extra uncertainty by swapping outputs of
Huffman codes in each state. Several test images are used for inspecting the
validity of the proposed Huffman Finite State Arithmetic Coding (HFSAC). The
results of several experimental, key space analyses, statistical analysis, key
sensitivity and plaintext sensitivity tests show that HFSAC with a little
effect on compression efficiency for image cryptosystem provides an efficient
and secure way for real-time image encryption and transmission.
