Experimental investigation on security of temporal phase coding OCDMA system with code-shift keying and differential phase-shift keying

We experimentally demonstrate security vulnerability in the temporal phase coding single-user DPSK- and CSK-OCDMA systems with a DPSK demodulator. In the systems without proper decoding, error free BER performance and clear open eye diagrams indicate the eavesdropping possibility for both systems. We also discuss the principle of DPSK demodulation attack.