Secret search system, secret search method, and computer readable medium

A secret search method for a secret search system including a management apparatus including a management memory unit;

• and a search apparatus, the management memory unit being a memory apparatus, wherein
• the management apparatus receives encrypted data and an encrypted tag and stores, in the management memory unit, the encrypted tag and the encrypted data such that the encrypted tag and the encrypted data are associated with each other, the encrypted data being obtained by encrypting storage data, and the encrypted tag being generated by performing encryption of a probabilistic encryption scheme on an associated keyword associated with the storage data,
• the search apparatus calculates deterministic information when the search apparatus obtains a search keyword for searching for the encrypted data stored in the management memory unit, generates a search query by performing encryption of the probabilistic encryption scheme on the search keyword using the deterministic information, and transmits the search query to the management apparatus, the deterministic information being uniquely determined by the search keyword,
• when the management apparatus receives the search query from the search apparatus, the management apparatus determines whether the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag stored in the management memory unit, and
• when the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag, the management apparatus stores, in the management memory unit, the deterministic information and the encrypted data associated with the encrypted tag such that the deterministic information and the encrypted data are associated with each other, the deterministic information being obtained by decrypting the search query.

A non-transitory computer readable medium storing a secret search program for a secret search system including a management apparatus including a management memory unit;

• and a search apparatus, the management memory unit being a memory apparatus, the secret search program causing a computer to perform:
• a data storage process of receiving encrypted data and an encrypted tag and storing, in the management memory unit, the encrypted tag and the encrypted data such that the encrypted tag and the encrypted data are associated with each other, the encrypted data being obtained by encrypting storage data, and the encrypted tag being generated by performing encryption of a probabilistic encryption scheme on an associated keyword associated with the storage data,
• a search query generation process of calculating deterministic information when a search keyword for searching for the encrypted data stored in the management memory unit is obtained, generating a search query by performing encryption of the probabilistic encryption scheme on the search keyword using the deterministic information, and transmitting the search query to the management apparatus, the deterministic information being uniquely determined by the search keyword,
• a determination process of determining, when the search query is received from the search apparatus, whether the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag stored in the management memory unit, and
• a deterministic information storage process of storing, when the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag, the deterministic information and the encrypted data associated with the encrypted tag in the management memory unit such that the deterministic information and the encrypted data are associated with each other, the deterministic information being obtained by decrypting the search query.

A secret search system comprising:

• a management apparatus including a management memory unit, and receiving encrypted data and an encrypted tag and storing, in the management memory unit, the encrypted tag and the encrypted data such that the encrypted tag and the encrypted data are associated with each other, the management memory unit being a memory apparatus, the encrypted data being obtained by encrypting storage data, and the encrypted tag being generated by encrypting an associated keyword associated with the storage data;
• and
• a search apparatus to calculate deterministic information when the search apparatus obtains a search keyword for searching for the encrypted data stored in the management memory unit, generate a search query by performing encryption of a probabilistic encryption scheme on the search keyword using the deterministic information, and transmit the search query to the management apparatus, the deterministic information being uniquely determined by the search keyword, wherein
• when the management apparatus receives the search query from the search apparatus, the management apparatus determines whether the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag stored in the management memory unit, and
• when the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag, the management apparatus stores, in the management memory unit, the deterministic information and the encrypted data associated with the encrypted tag such that the deterministic information and the encrypted data are associated with each other, the deterministic information being obtained by decrypting the search query.

A secret search method for a secret search system including a management apparatus including a management memory unit;

• and a search apparatus, the management memory unit being a memory apparatus, wherein
• the management apparatus receives the encrypted data and an encrypted tag and stores, in the management memory unit, the encrypted tag and the encrypted data such that the encrypted tag and the encrypted data are associated with each other, the encrypted data being obtained by encrypting storage data, and the encrypted tag being generated by encrypting an associated keyword associated with the storage data,
• the search apparatus calculates deterministic information when the search apparatus obtains a search keyword for searching for the encrypted data stored in the management memory unit, generates a search query by performing encryption of a probabilistic encryption scheme on the search keyword using the deterministic information, and transmits the search query to the management apparatus, the deterministic information being uniquely determined by the search keyword,
• when the management apparatus receives the search query from the search apparatus, the management apparatus determines whether the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag stored in the management memory unit, and
• when the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag, the management apparatus stores, in the management memory unit, the deterministic information and the encrypted data associated with the encrypted tag such that the deterministic information and the encrypted data are associated with each other, the deterministic information being obtained by decrypting the search query.

A non-transitory computer readable medium storing a secret search program for a secret search system including a management apparatus including a management memory unit;

• and a search apparatus, the management memory unit being a memory apparatus, the secret search program causing a computer to perform:
• a data storage process of receiving encrypted data and an encrypted tag and storing, in the management memory unit, the encrypted tag and the encrypted data such that the encrypted tag and the encrypted data are associated with each other, the encrypted data being obtained by encrypting storage data, and the encrypted tag being generated by encrypting an associated keyword associated with the storage data,
• a search query generation process of calculating deterministic information when a search keyword for searching for the encrypted data stored in the management memory unit is obtained, generating a search query by performing encryption of a probabilistic encryption scheme on the search keyword using the deterministic information, and transmitting the search query to the management apparatus, the deterministic information being uniquely determined by the search keyword,
• a determination process of determining, when the search query is received from the search apparatus, whether the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag stored in the management memory unit, and
• a deterministic information storage process of storing, when the search keyword obtained by decrypting the search query matches the associated keyword obtained by decrypting the encrypted tag, the deterministic information and the encrypted data associated with the encrypted tag in the management memory unit such that the deterministic information and the encrypted data are associated with each other, the deterministic information being obtained by decrypting the search query.