1. A computer-implemented method for comparing anonymized data entries, comprising: (a) accessing a first list having a plurality of anonymized first entries, wherein an anonymized first entry includes a first part and a first score, and wherein the first part is anonymized; (b) accessing a second list having a plurality of anonymized second entries, wherein an anonymized second entry includes a second part and a second score, and wherein the second part is anonymized; (c) detecting an exact match between the first part and the second part; and (d) determining validity of said match based on a comparison of the first score and the second score to a threshold, wherein the first score is based on derivational history of the first part, and wherein the second score is based on derivational history of the second part.
9. The method of claim 1 , wherein determining the validity, comprises comparing the first score and the second score to a threshold.