Successful message encoding/decoding in an unpredictability-enhanced chaotic vertical-cavity surface-emitting lasers (VCSELs) system is achieved numerically via the chaos-shift-keying technique. Both VCSELs are subject to variable-polarization optical feedback (VPOF), and polarization-preserved optical injection is adopted. Better decoding performance is achieved by choosing proper polarizer angle, and the security is, to some extent, enhanced owing to the VPOF.