A system includes a security device, configured for cryptographic processing, coupled to receive incoming data from a plurality of data sources (e.g., data from different customers), wherein the incoming data includes first data from a first data source; a controller (e.g., an external key manager) configured to select a first set of keys from a plurality of key sets, each of the key sets corresponding to one of the plurality of data sources, wherein the first set of keys is used by the security device to encrypt the first data; and a common encrypted data storage, coupled to receive the encrypted first data from the security device.