Techniques

The threat actor (Eve) may initially compromise the quantum channel in order to access the quantum communication. Once compromised, the threat actor can perform a multitude of quantum attack techniques.

The Laser Seeding Attack (LSA) involves manipulating the intensity of the light emitted by a laser diode in a QKD system's transmitter (Alice) by injecting continuous-wave (CW) laser light at a specific wavelength. This injection stimulates the emission, boosting the transmitter's output power and altering the characteristics of the emitted pulses, thereby compromising the security of QKD protocols by enabling attackers to gain knowledge of the light's phase and potentially opening doors for further quantum attacks.

In the Laser Seeding Attack tailored for two-way quantum key distribution schemes, the threat actor (Eve) manipulates the intensity of the optical pulses within the system by intercepting and replacing the pulses the receiver (Bob) sends to the transmitter (Alice) with ones of higher intensity. This strategic replacement forces Alice to encode her information on these intensified pulses, inadvertently increasing the intensity of the signals she sends back to Bob, compromising the system's security.

The Injection-Locking Attack (ILA) on quantum key distribution systems involves the threat actor (Eve) injecting a strong laser beam into the transmitter's (Alice's) laser source. This forced synchronization makes Alice's laser resonate at Eve's designed frequency, subtly altering the emitted pulses' frequency based on their polarization states. This manipulation enables Eve to infer the polarization used by Alice, laying the groundwork for direct key extraction or facilitating subsequent photon number splitting (PNS) attacks.

The threat actor (Eve) can exploit an imperfect channel transmittance model in continuous-variable quantum key distribution (CV-QKD) systems to overestimate the secret key length by biasing parameter estimation through intercept-and-resend attacks, leveraging issues like atmospheric turbulence and background noise.