ANONYMOUS SEARCH SYSTEM, ANONYMOUS SEARCH METHOD, AND ANONYMOUS SEARCH PROGRAM

摘要

A management apparatus (500) stores encrypted tags (C(D)) and encrypted data such that they are associated with each other. When a search apparatus (400) obtains a search keyword (s) for searching for encrypted data stored in the management apparatus (500), the search apparatus (400) calculates deterministic information (t) which is uniquely determined by the search keyword (s), and generates a search query (Q(s)) by performing encryption of a probabilistic encryption scheme on the search keyword (s) using the deterministic information (t). The search apparatus (400) transmits the search query (Q(s)) to the management apparatus (500). When the management apparatus (500) receives the search query (Q(s)) from the search apparatus (400), the management apparatus (500) determines whether the search keyword (s) obtained by decrypting the search query (Q(s)) matches an associated keyword obtained by decrypting an encrypted tag (c) stored in the management apparatus (500).