Study of security for chaotic communication system based on semiconductor lasers

The influences of feedback coefficient to the security of chaotic communication system based on semiconductor lasers subject to external optical feedback are studied in this paper. The synchronization error and decoding performance at different mismatch in photo lifetimes of transmitter and receiver are studied. The results shows the strong feedback at transmitter laser increases the complexity of the chaos, which makes the eavesdropping difficult, reduces the mismatch range can be used by attacker, and improve the security of the system. Large photo lifetime at transmitter contribute to prevent the attacker with a specified percent of mismatch from eavesdropping. It also indicates that it is difficult for the attacker to recover the information with high bit rate when the feedback at transmitter is high.