Security in data communication and privacy in conversations for underwater wireless networks using scrambled speech scheme

摘要

In this paper, a secure scheme for underwater telecommunication networks has been proposed. The main idea stems from the fact that all telecommunication networks, including underwater networks, have been basically prepared to transfer speech and voice. In our proposed scheme, the input voice is transformed to the bit stream using a low bit rate encoder. Then, the whole bits are mapped to the predefined symbols, which have been originally designed using hi-fi speech records. Symbols are stored in a lookup table in the both sides of channel. At transmitter side, the prepared signal is windowed, filtered and shaped to transfer over underwater link. The overall bit error rates are as low as that have not any significant effect on quality of speech while, on the other hand, the output noises are quite unintelligible for intruders who try to access to the conversations through the channel of telecommunication network. Produced noises are signals including random scrambled speech-based symbols in which make no any sense to the listener. The simulated system was considered to transfer speech to obtain results in an experimental state. The results show that the proposed scheme for underwater telecommunication is reliable.