Defending wireless communication against eavesdropping attacks using secret spreading codes and artificial interference

The broadcast nature of wireless communication makes it intrinsically vulnerable to eavesdropping attacks. This article suggests the using of secret spreading codes (i.e. only a legitimate receiver knows the spreading sequence) and artificial interference (i.e. by intentionally adding noise to the broadcast channel) on countering eavesdropping attacks. We have made a theoretical analysis on the potential performance degradation at the eavesdropper and at the legitimate receiver for a point-to-point wireless communication system using direct-sequence spread spectrum (DSSS) with coherent phase-shift keying (PSK) modulation. We have also proposed a lightweight non-cryptographic secret code generation scheme which leads to low correlation between the spreading codes used at the transmitter and at the eavesdropper. Simulation results confirms the good anti-eavesdropping performance on using the proposed non-cryptographic secret code generation scheme. Simulation results also conform with the theoretical analysis and motivate the using of artificial interference on countering eavesdropping attacks.