Abstract: A method for determining whether data is included in a database is described. In one embodiment, the method may include receiving, from a remote computing device, a search request that includes a portion of a signature, comparing the portion of the signature with a plurality of signatures stored at the database, determining whether at least one match exists between the portion of the signature and the plurality of signatures, upon determining at least one match exists, identifying each match and identifying a bloom filter that includes each match, and transmitting the bloom filter to the remote computing device.

Abstract: A method for determining whether data is included in a database is described. In one embodiment, the method may include receiving, from a remote computing device, a search request that includes a portion of a signature, comparing the portion of the signature with a plurality of signatures stored at the database, determining whether at least one match exists between the portion of the signature and the plurality of signatures, upon determining at least one match exists, identifying each match and identifying a bloom filter that includes each match, and transmitting the bloom filter to the remote computing device.

Abstract: A method for user credential location using prefix matching is described. In one embodiment, the method may include enabling a user to generate remotely a cryptographic hash of a user credential of the user, receiving a portion of the cryptographic hash from the user, comparing the portion of the cryptographic hash with a plurality of cryptographic hashes of user credentials stored at a database, determining whether a match exists between the portion of the cryptographic hash and at least one of the plurality of cryptographic hashes, and transmitting a notification to the user indicating whether the user credential is stored at the database based at least in part on a result of the comparing.