Abstract: To investigate the multiplexed communication in a chaos system with semiconductors subject to optical feedback and optical injection where delays are modulated by signals, the encryption is realized through modulating the channel delay with the corresponding user's signal and the decryption is implemented utilizing chaos synchronization and cross correlation measurement by numerical simulation. The multiplexing and de-multiplexing of three user's signals of 1Gbit/s were realized. Also, the conditions for efficient decryption and the main factors affecting bit error were analyzed.