Data mining or knowledge discovery, is the computer-assisted process of digging through and analyzing enormous sets of data and then extracting the meaning of the data. Data mining tools predict behaviors and future trends, allowing businesses to make proactive, knowledge-driven decisions. Data mining derives its name from the similarities between searching for valuable information in a large database. The paper presented the Concealed Data Aggregation (CDA) scheme extended from homomorphic public encryption system. It designed for a multi-application environment and the base station extracts application-specific data from aggregated cipher texts.