Which spoofing technique involves replaying legitimate signals to mislead receivers?

Which spoofing technique involves replaying legitimate signals to mislead receivers?

• A. Simulated signals
• B. Replay attack
• C. Time-delay spoofing
• D. Broadcast hijacking

Answer: (B)

The main idea here is a technique where an attacker captures a legitimate satellite signal and later retransmits that exact signal to a receiver, making it look like a fresh transmission. Because the replayed data is identical to a valid past transmission, the receiver may accept it as current if there aren’t proper freshness checks like timestamps or sequence numbers. This is the essence of a replay attack — using a previously valid signal again to mislead the system. Other options involve different concepts: creating new forged signals rather than reusing a past one, or intentionally delaying the signal to distort timing, or taking over the broadcast channel to inject content. None of these rely on re-sending the exact original transmission, which is what makes the replay attack the best fit for this scenario. Defensive measures include adding freshness checks, nonces, timestamps, or rolling codes to ensure the system can detect and reject replayed signals.

The main idea here is a technique where an attacker captures a legitimate satellite signal and later retransmits that exact signal to a receiver, making it look like a fresh transmission. Because the replayed data is identical to a valid past transmission, the receiver may accept it as current if there aren’t proper freshness checks like timestamps or sequence numbers. This is the essence of a replay attack — using a previously valid signal again to mislead the system.

Other options involve different concepts: creating new forged signals rather than reusing a past one, or intentionally delaying the signal to distort timing, or taking over the broadcast channel to inject content. None of these rely on re-sending the exact original transmission, which is what makes the replay attack the best fit for this scenario. Defensive measures include adding freshness checks, nonces, timestamps, or rolling codes to ensure the system can detect and reject replayed signals.