Active RIS-Empowered Signal Cancellation Attacks.

When reconfigurable intelligent surface (RIS) is used to initiate attacks without actively generating sources of jamming signals, signal cancellation attacks (SCAs) are the main methods. However, a passive RIS (PRIS) requires a lot of reflecting elements in order to obtain considerable SCAs when attacked systems limit signal leakage to non-target receivers. This puts the PRIS at high risk of being tracked and monitored by enemies. To increase the flexibility of RIS deployment while maintaining a significant attack, this correspondence proposes active RIS (ARIS) to implement SCAs, which is exact opposite to the original intention of proposing ARIS to improve transmission quality. Specifically, with constraints on maximum reflecting amplitude and maximum amplification power, we derive a signal-to-interference-plus-noise ratio (SINR) minimization problem. In order to achieve a fast attack, an algorithm with low complexity is proposed to resolve the non-convex problem. Numerical results show that ARIS can perform a stronger SCA than PRIS under more stringent conditions.