Multi scrolls chaotic encryption scheme for CO-OFDM-PON

Abstract

In this paper, we propose and experimentally demonstrate a novel multi scrolls chaotic encryption scheme for CO-OFDM-PON. We analyze the principle of 3-dimension encryption scheme and discuss its encryption complexity. Compared with the previous hyper Chen chaotic encryption scheme, the proposed encryption algorithm can realize dynamic constellation point mapping of QAM signal with lower encryption complexity. We also compare the transmission performances of the two chaotic encryption schemes. The results show that the proposed multi scrolls scheme has better BER performance because it can decrease the peak to average power ratio (PAPR) of OFDM. What is more, the proposed encryption scheme is very sensitive to the initial secure key and a tiny discrepancy as small as 10-17 would lead to a completely different sequence. The high sensibility to the initial value can effectively increase encryption level and the key space of the multi scrolls encryption scheme is 106 times of that hyper Chen. Further, to verify the effectiveness of the proposed encryption algorithm, encrypted transmission of a digital picture in 80 km SSMF is carried out.