For protecting physical layer of optical fiber communication systems, quantum stream cipher called Y-00 and Alpha-Eta is promising. So far, we demonstrated secure and high speed optical fiber communication experiments using Y-00 quantum stream cipher. Our theoretical research revealed that the randomization techniques could enhance the security performance. In this work, we fabricated a novel Y-00 transceiver for GbE where the randomization technique was implemented. The transceiver employed the optical intensity modulated Y-00 quantum stream cipher with intensity levels of 4096. An appropriately designed irregular mapping as the randomization technique was experimentally demonstrated. The transceiver was successfully applied to secure optical fiber transmission of GbE signals.