Abstract
The security of communications in various transmitted information’s forms such as video, audio, image, and even text
and preserving them from attackers has become of great importance in the age of the Internet and cellular networks.
Perhaps one of the most important media used to transmit information is digital images. They are distinguished from
video and audio by their lack of complexity, and at the same time they are distinguished from text by the possibility
of containing more information. Due to the necessity of transmitting huge amounts of information via digital images
through additive white Gaussian noise (AWGN) channels for various applications. This transmission of images over
unsecured channels is vulnerable to many attacks that must be protected by information security tools. In this research,
a hybrid chaos-based system was developed to encrypt and secure images and send them via an orthogonal frequency
division multiplexing (OFDM) channel, which leads to transferring large amounts of transmitted information in a short
time, with very little interference between the data, and maintaining the transfer rate. Two chaotic techniques, Rossler
and Modified Chau system, are used together to create a secret encryption key. This combination of chaotic systems
provides highly random sensitive keys with amplitude of 10252 that are difficult to predict by the attacker and which
makes restoring the original image very difficult in the event of a very small change in the chaotic parameters. Many
tests were conducted to determine the strength of the proposed system, including statistical and differential analysis
and entropy to verify the strength of the image security approach, in addition to applying some types of attacks to the
encrypted image, such as noise and cropping different parts of the image. It is clear that the proposed scheme has strong
immunity to these attacks. This was proven by the comparative experimental results. The entropy ratio was very excellent
compared to the rest of the results obtained in the rest of the research. This was also the case with the values of (NPCR),
(UACI), (NPCR), and Mean Square Error (MSE) was also very good as compared with other researches in the literature.
The proposed security approach for OFDM gave a low link and a low bit error rate. And a higher signal-to-noise ratio
(PSNR).