Bit Error Rate: A Key Indicator for Detecting Attacks in Optical Communication

To enhance the accuracy of signal legitimacy assessment in optical communication, we utilize the bit error rate (BER) as a key indicator. By establishing a predefined valid BER range (T), as illustrated in formula 5, we can effectively differentiate between legitimate and malicious activities.

In the absence of attacks, specifically at instances k, K-1, and K-2, we measure variables A, B, and C. These values are then incorporated into equations 3 and 4 to calculate the permissible BER range, denoted as T. This threshold, T, serves as a critical benchmark for determining the security status of the system.

Normal optical communication systems exhibit BER fluctuations within a specific, relatively stable range. However, malicious activities such as eavesdropping or forgery by an adversary (Eve) introduce significant deviations in the BER. These actions increase both the fluctuation range and the overall BER value.

When the BER surpasses the predefined threshold T, it signals an ongoing attack, resulting in authentication failure. Conversely, if the BER remains within the acceptable T range, the system is deemed secure, and authentication is successful.

Therefore, by continuously monitoring and analyzing the BER against the established threshold T, we can effectively detect and mitigate security threats in optical communication systems.