A hashing scheme is used to facilitate identifying the presence of matching information items on different network nodes without disclosing the information.

摘要

The presence of matching information items in a network is identified by: using a hashing scheme to generate first hash values from respective first information items (e.g. friend/contact information) stored at a first node S402; transmitting the first hash values to a second node S404; comparing the first hash values at the second node with second hash values generated, using the hashing scheme, from respective second information items stored in the network S406; determining at least one matching hash value between the first and second hash values S408; using the determined value to identify the presence of a matching information item between the first and second information items, wherein the hashing scheme is chosen to ensure sufficient collisions so that a unique hash value in the hashing scheme indicates a sufficient number of information items to prevent the unique hash value being used as an identifier of a unique information item. Consequently the transmission of the first hash values to the second node does not disclose the first information items to the second node.