In one aspect, a computerized Encrypted Drive System (EDS) server useful for keyword extraction and indexing server of includes a computer store containing data, wherein the data. The data includes an unencrypted document file and a computer processor in the EDS server. The computer processor obtains the unencrypted document file from the computer store. The computer processor extracts a keyword information from the unencrypted document file. The keyword information comprises of a set of keywords appearing in the unencrypted document file. The computer processor includes one or more colors from the color-set of each keyword into a document color-index of the unencrypted document file. The computer processor generates a Bloom filter encoding a set of keywords stored in a metadata field and the unencrypted document file, and wherein the Bloom filter is used to represent the set of keywords in the unencrypted document file.