Confidentiality performance of spectral-phase-encoded optical CDMA

Security Limitations of Spectral Amplitude Coding Based on Modified Quadratic Congruence Code Systems

“…Therefore, when just a single user is active, optical CDMA system cannot guarantee physical layer security any more. In certain time, this situation can be existed even in a multiuser active optical CDMA network as reported in current theoretical analyses (Shake 2005a(Shake ,2005b. …”

“…Other approaches to enhance security have been proposed using optical encoding techniques such as fiber bragg gratings (FBG) to implement optical CDMA systems (Shake 2005a(Shake ,2005b. Their degree of security depends on code dimensions being used.…”

Dynamic scrambling scheme of arrayed-waveguide grating-based encryptors and decryptors for protection against eavesdropping

“…However, Shake [9,10] identified several weaknesses of OCDMA systems, including their eavesdropping susceptibility. Therefore, constructing effective security mechanisms for OCDMA systems is crucial when designing the physical layer.…”

“…In addition, OCDMA techniques provide strong data security and enhance user signal confidentiality [1][2][3][4][5][6][7][8]. Shake [9,10] demonstrated two strategies for enhancing the robustness of OCDMA networks against unauthorized users by increasing the code complexity (i.e., increasing the code space size) and reducing the subscribers' transceiver power. However, a changing codeword mechanism is yet to be demonstrated.…”

Measurements of eavesdropping in a wavelength/time optical CDMA (O-CDMA) system, with data confidentiality implications

“…Tančevski [1] proposes that O-CDMA can provide a very large code space for secure communications; but recent analyses of current implementations of O-CDMA found that this may not provide a high degree of data confidentiality (Shake [2,3]). References [2], [3] in particular concentrated on analyses that followed Kerckhoffs' principle (i.e., that the eavesdropper/intruder knows all about the user's codes) and where the eavesdropper has tapped the encoded signal prior to it being comingled with MAI. Reference [2] applied this methodology to the cases of wavelength/time codes where the weight W is high (31 or 101) and where the code dimension n c x n λ is also high (961x31 and 10201x31); here n c = number of time chips in the 2D code and n λ = number of wavelengths in the code.…”