Patent ID: 7783899

Claim:
A method for providing a conjunctive keyword search over encrypted data, comprising: generating on a requestor comprising an user computer, a plurality of encrypted data, each data identified with an encrypted keyword vector comprising a plurality of keyword fields that each contains a keyword associated with the encrypted data; maintaining on a server the encrypted data and encrypted keyword vectors generated on the requestor; defining on the requestor a conjunctive keyword query comprising: choosing a plurality of query keywords; encrypting the chosen keywords; and conjunctively combining the encrypted keywords as a plurality of parameters to comprise the conjunctive keyword query; generating a capability from the conjunctive keyword query and sending, the capability from the requestor to the server; generating at the server an encrypted result comprising: applying the capability exclusively to the encrypted keyword vectors and generating the encrypted result comprised of only the encrypted data identified by the keyword vectors that satisfy the capability; and providing to the requestor the encrypted result; and determining at the requestor an answer to the conjunctive keyword query solely through decryption of the encrypted result.