The acoustic encryption transmission system based on improved DEA

The system adopts the improved data encryption algorithm(DEA), and the hardware encryption system is constructed by complex programmable logic device(CPLD) chip EPM570. After frequency modulation, the acoustic signal is encrypted by key and sent to the receiving end. The receiving end is filtered and the original signal is restored after key decryption, so that the close-range encrypted transmission can be realized. The hardware circuit is divided into two parts: the sender and the receiver, which are composed of the main controller, CPLD, direct digital synthesizer(DDS),filter and reed-solomon(RS) codes module circuits. Experiments show that the system has high security and can be applied to the transmission of confidential or sensitive signals.