Query issued and user secret key generation method and encryption method and the public parameter generation method and confidential search method and computer program and query and retrieval device issuing device and user private key generation apparatus and encryption device and the public parameter generating device and confidential search system search method and how

摘要

Even if the secret retrieval system for multiple users, the size of the ciphertext is small, a new user is added, I eliminate the need to generate a new encrypted text. Public parameter generating unit 100 generates a pair of the master secret key and public parameters. Using the public parameters, encrypts the keyword, the encryption apparatus 400 generates a ciphertext. And using the master secret key, user private key generation device 200 generates a private key of a user query issuing device 300. Query issuing device 300 generates a query using the user private key, searching for keywords. Based on the cipher text queries, the search unit 500 determines whether the document is retrieved.