Hybrid software-hardware image encryption techniques for network security using multiple chaotic maps

The security of digital data transmission has become a primary concern in this century, particularly in the field of information data communication. Encryption is the process of transforming information to prevent unauthorized access and plays a critical role in ensuring data security. The two proposed techniques support four distinct Chaos Pseudo Random Bit Generators (PRBGs): Lozi map, Tent map, Logistic map, and Quad map. The image is split into four parts, each encrypted using one of the mentioned PRBG maps, thereby enhancing the complexity and security of the encryption system. The randomness of the generated cryptographic keys was tested using the National Institute of Standards and Technology (NIST) Statistical Test Suite for evaluating Pseudorandom Number Generators for Cryptographic Applications. The overall encryption system was implemented on a Field Programmable Gate Array (FPGA) ZYNQ702 evaluation board hardware device. The results were compared with those of other researchers to evaluate improvements in the NIST Statistical Test Suite outcomes relative to existing methods, aiming to identify the most effective encryption approach. The main contributions of this paper include two systems offering more secure and effective methods, supported by comparisons with other studies, thereby advancing secure data transmission using FPGA technology at a frequency of 667 MHz and a throughput of 5.3 Gbps.