Joint Research Integrated for Integrated System, Department of Electrical, Electronic & Computer Engineering, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK.
Opt Lett. 2011 May 1;36(9):1623-5. doi: 10.1364/OL.36.001623.
We propose and experimentally demonstrate a time-domain bit-by-bit code-shifting scheme that can rapidly program ultralong, code-length variable optical code by using only a dispersive element and a high-speed phase modulator for improving information security. The proposed scheme operates in the bit overlap regime and could eliminate the vulnerability of extracting the code by analyzing the fine structure of the time-domain spectral phase encoded signal. It is also intrinsically immune to eavesdropping via conventional power detection and differential-phase-shift-keying (DPSK) demodulation attacks. With this scheme, 10 Gbits/s of return-to-zero-DPSK data secured by bit-by-bit code shifting using up to 1024 chip optical code patterns have been transmitted over 49 km error free. The proposed scheme exhibits the potential for high-data-rate secure optical communication and to realize even one time pad.
我们提出并实验验证了一种基于时域逐比特码移位的方案，该方案通过仅使用色散元件和高速相位调制器，可以快速编程超高速、码长可变的光码，从而提高信息安全性。所提出的方案在比特重叠区域工作，可以消除通过分析时域光谱相位编码信号的精细结构来提取码的脆弱性。它还固有地免疫通过传统的功率检测和差分相移键控（DPSK）解调攻击进行的窃听。利用该方案，在 49km 无差错传输距离上，使用多达 1024 个光码片的逐比特码移位，成功传输了 10Gbps 的归零-DPSK 数据。该方案具有实现高速率安全光通信的潜力，甚至可以实现一次一密。
