Co-design based FPGA implementation of an efficient new speech hyperchaotic cryptosystem in the transform domain

In this paper a new encryption system has been designed and implemented for real-time speech transmission to reduce bandwidth requirements, increase security and minimize residual intelligibility. To guarantee robustness and lightweight computation, the developed cryptosystem has been carried out in the wavelet transform domain based on a hyperchaotic model to generate mask and permutation keys. The cryptographic system has been designed using a hardware-software (HW/SW) co-design approach by developing several IP-cores in a relatively short development time. The performances and security evaluation of the system have been validated through simulation results followed by an experimental validation through the implementation of an encrypted speech signal transmission between two low cost Nexys-4 DDR FPGA platforms, operating in real-time for both wired and wireless communications. Compared to similar works, high performances have been obtained in terms of bandwidth efficiency due to the use of DWT, limited area of FPGA resources, low power consumption and high security level with a large keyspace that is sufficient to resist against brute force attacks. The designed system can be a very useful solution for many real-time secure integrated voice communication systems, multiple communication purposes, military, professional or personal high level of conversations security.