A risk engine device of an enterprise's authentication system is configured to apply a Bloom filter algorithm to a master authentication list from a database to generate the Bloom filtered authentication list. Once generated, the risk engine device stores the Bloom filtered authentication list as part of an associated cache memory. Because the Bloom filtered authentication list is smaller in size relative to the master authentication list, by utilizing the Bloom filtered authentication list, the risk engine device decouples the linear dependency between the master authentication list and cache memory consumption, thereby reducing the relatively excessive cache memory use found in conventional risk engines.