Bit Error Rate Fluctuation: An Effective Indicator for Detecting Attacks in Optical Communication Systems

To enhance the accuracy of signal legitimacy judgment in optical communication systems, we introduce a novel approach based on bit error rate (BER) fluctuation analysis. As depicted in Formula 5, a legitimate BER range (T) is established. This range is derived from measurements taken at specific time points (k, K-1, and K-2) when the system is confirmed to be free from any attacks. During these periods, parameters A, B, and C are meticulously measured and incorporated into Equations 3 and 4 to calculate the permissible range T. This calculated range serves as a crucial indicator for detecting potential attacks targeting the system. In a typical optical communication system, the BER demonstrates inherent fluctuations within a predefined range, characterized by relatively small variations. However, malicious activities, such as eavesdropping or data forgery by an adversary (Eve), introduce significant disturbances to the transmission link. These actions result in a noticeable increase in the BER fluctuation range, leading to a higher BER value. Our proposed security mechanism leverages this characteristic behavior of BER. If the measured BER surpasses the predefined threshold T, it signifies the presence of an attack, triggering an immediate authentication failure. Conversely, when the BER remains within the bounds of T, it confirms the absence of any malicious activities, ensuring successful authentication and secure communication.