Double all-optical encryption of M-QAM signals based on spectrally sliced encoding keys

Abstract

The ever-growing demand for optical network security can be addressed by data encryption at different network layers. In this work, we consider all-optical cryptography technique that applies a spectral phase change and delay encoding on spectrum slices of a specified WDM channel. In this case we have investigated a novel approach where signals are double encrypted to achieve an enhanced degree of security. Simulation results indicate that such double cyphering scheme can be applied to high data-rate M-QAM signals propagating in metro/regional networks.

Security threats and protection procedures for optical networks

“…The encryption is performed by encoding independently spectral slices of an optical signal with a precise amount of phase shift and delay, making the signal recovery impossible unless the opposite delay and phase shifts are applied. This has been demonstrated numerically with M‐QAM modulated data with bit rates of up to 200 Gb/s [21]. However, this method requires a very accurate spectral alignment between the spectral phase coder and decoder.…”

“…Indeed, a slight frequency misalignment between the phase mask at the encoder and the reverse phase mask at the decoder might lead to a very large penalty preventing from correct signal recovery. To illustrate this issue, we performed numerical simulations (as described in the Appendix) with the spectral phase mask used in [21] and shown in Fig. 11 a .…”

Aplicação de Algoritmo Genético para Determinação de Chaves Usadas em Criptografia Óptica Mediante Fatiamento Espectral

“…Contudo, apesar de conceitualmente promissora, o mecanismo de sincronização entre o receptor e o transmissor requerido por essa abordagem ainda não pode ser atendido em redes comerciais. Outros esquemas baseiam-se na implementação de codificação espectral de fase (spectral phase encoding, SPE) [6], codificação espectral de amplitude (spectral amplitude encoding, SAE) [7] e codificação espectral de atraso (spectral delay encoding, SDE) [7][8][9][10]. Essas três estratégias são interessantes por serem aplicadas a canais compatíveis com a tecnologia de multiplexação por divisão em comprimento de onda (wavelength division multiplexing, WDM) e, portanto, em princípio, podem ser usadas em redes comerciais.…”

“…Em particular, [8][9][10] maliciosos. Conforme a descrição da Seção II, essas chaves são determinadas a partir de parâmetros de fase e de atraso escolhidos para distorcer os sinais que serão criptografados.…”