The data security method, system and associated data mining enables multiple users, each having a respective security clearance level to access security sensitive words, data objects, characters or icons. The method extracts security sensitive words, data objects, characters or icons from plaintext or other source documents to obtain (a) subsets of extracted data and (b) remainder data. The extracted data is, in one embodiment, stored in a multilevel security system (MLS) which separates extract data of different security levels with MLS guards. Some or all of the original data is reconstructed via one or more of the subsets of extracted data and remainder data only in the presence of a predetermined security level. In this manner, an inquiring party, with the proper security clearance, can data mine the data in the MLS secured storage.