Abstract: A URL reputation system may have a reputation server and a client device with a cache of reputation information. A URL reputation query from the client to the server may return reputation data along with probabilistic set membership information for several variants of the requested URL. The client may use the probabilistic set membership information to determine if the reputation server has additional information for another related URL as well as whether the classifications are inheritable from one of the variants. If the probabilistic set membership determines that the reputation server may have additional information, a query may be made to the reputation server, otherwise the reputation may be inferred from the data stored in the cache.

Abstract: A URL reputation system may have a reputation server and a client device with a cache of reputation information. A URL reputation query from the client to the server may return reputation data along with probabilistic set membership information for several variants of the requested URL. The client may use the probabilistic set membership information to determine if the reputation server has additional information for another related URL as well as whether the classifications are inheritable from one of the variants. If the probabilistic set membership determines that the reputation server may have additional information, a query may be made to the reputation server, otherwise the reputation may be inferred from the data stored in the cache.