Abstract: A system, a computerized apparatus, a computer program product and a method performed in an environment comprising an on-premise system and an off-premise system, the on-premise system retaining records. Each record comprising a personal identifying information (PII) representing a person and data comprising sensitive data regarding the person. The identity of the person is obtainable from the PII but not from the data. The method comprising: obtaining, by the on-premise system, the PII of a record representing a person; providing at least a portion of the PII to the off-premise system, wherein the off-premise system is configured to obtain enriched data associated with the person; receiving, by the on-premise system, the enriched data from the off-premise system; and training a classifier using the data and the enriched data, wherein the classifier is being trained without relying on the personal identifying information.