This letter investigates reduction in the degree of cyclostationarity (DCS) of digital communication signals in the presence of polarization diversity. Reduction in DCS decreases the probability of detection of an intruder that searches for periodic patterns in the transmitted signal. We propose a DCS reducing scheme that exploits dual-polarization diversity when correlated wide sense stationary information streams with different rates and codes are transmitted over polarizations assuming a uni-polarized adversary. The effects of depolarization and data correlation across polarizations on both the DCS experienced by the adversary, and the resulting probability of detection are investigated.