| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain the co-occurrence number of two attributes without revealing data to other users as much as possible. <P>SOLUTION: Each identifier included in a predetermined number of data blocks or less is read from a plurality of data blocks each having a common identifier and an attribute value. Any one of hash values the number of which is limited to a predetermined number is calculated for each read identifier using a common hash function. An identifier is stored in a data storage unit in association with the hash value. For each of the predetermined number of hash values, if one or more identifiers are associated with the hash value, 0 or 1 is specified based on an attribute value included in a data block including any one of the identifiers. If any identifiers are not associated with the hash value, 0 is specified. This allows a vector having a predetermined number of element values to be generated. Each element value of the vector is enciphered by a predetermined method and transmitted to another device. An inner product value of the enciphered vector is received from the other device. The inner product value of the vector is then decrypted. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
