Bits and Characters Substitutions to Increase the Security Level of Transmitted Secret Message

Chaotic logistic map model is an interesting tool, it has good features, which make it capable to create chaotic keys, these keys are stable and sensitive to the selected values of chaotic parameters. In this paper research we will introduce a simple, secure and efficient method of secret message cryptography. The encryption-decryption phases will be implemented in two rounds. Two secret keys will be used; these keys will be generated by running two CLMM with a selected chaotic parameter. The first key 'CSK' will be used for message characters' substitution, while the second secret key 'BSK' will be used for message binary version bits' substitution. The two secret keys will be generated using a PK which contains the selected values of the CLMM. The PK will provide a huge key space capable to resist any hacking attack, also the generated two keys will be sensitive to any changes in the PK components, making any minor changes in these components in the decryption phase will be considered as a hacking attempt. The proposed method will be implemented using various messages, the obtained results will be analyzed using various types of data analysis method to prove the quality, security and the efficiency of the proposed method.