A system for anonymizing and aggregating protected information (PI) from a plurality of data sources includes a master index server coupled to a data repository. The master index server receives an anonymized records associated with an individual from a plurality of data hashing appliances. The system includes a cluster matching engine that applies a plurality of rules to hashed data elements of the received record for comparing hashed data elements of the record with hashed data elements of a plurality of clusters of anonymized records associated with different individuals stored in the data repository to determine whether the individual associated with the received record corresponds to an individual associated with one of the clusters of anonymized records. When a match is found, the cluster matching engine adds the received record to the cluster of anonymized records associated with that individual.