The present invention relates to a computer-implemented method, system and computer readable medium for searching over encrypted keywords in a database. The method includes the steps of generating at least one keyword, generating a plurality of different encrypted keywords corresponding to the keyword, storing the at least one encrypted keyword in the database, generating a plurality of different trapdoors for the keyword, verifying the plurality of different trapdoors with the plurality of different encrypted keywords corresponding to the keyword, and determining the keyword is found if the plurality of different trapdoors match with one the encrypted keyword corresponding to the keyword, otherwise determining the keyword is not found.