Keyword batch privacy information retrieval method and system based on full homomorphism

The invention belongs to the technical field of information retrieval, and provides a keyword batch privacy information retrieval method and system based on full homomorphism. The keyword batch privacy information retrieval method based on full homomorphism comprises the following steps: dividing all privacy data in a privacy data set into a plurality of data blocks by a server, and constructing a position information set table corresponding to the privacy data set based on a Hash algorithm; each keyword in the position information set table is set as a piece of privacy data, and the keyword and the block position and the in-block position of the privacy data corresponding to the keyword are stored in an associated manner; the same keywords are recorded in the repeated privacy data, and the position information is expanded backwards; and the client inquires the position information set table, determines the position of the privacy data to be inquired in the corresponding data block, encrypts the determined po