Data masking

Abstract

Data masking is provided by, for at least one predetermined data item in data to be sent, applying a one-way function to that data item to produce a first value, producing a masked data item by encrypting the first value via a deterministic encryption scheme using a current encryption key for a current epoch, and replacing that data item by the masked data item. A data-provider computer sends the masked data to the data-user computer. On expiry of the current epoch, the data-provider computer generates a new encryption key for the encryption scheme in a new epoch, produces mask-update data, dependent on the current and new encryption keys, and sends the mask-update data to the data-user computer. The mask-update data permits updating, at the data-user computer, of masked data items produced with the current encryption key into masked data items produced with the new encryption key.

Dependencies are inferred from the claim text.