The false positive rate is a measure used to evaluate the performance of an IDS (Intrusion Detection System). It is calculated by dividing the number of false positives (FP) by the sum of false positives and true negatives (TN). The formula is:
False Positive Rate=FP+TNFP
This formula helps in determining how often the IDS incorrectly classifies an event as a threat, which is actually benign. A lower false positive rate indicates a more accurate IDS.