Abstract: A system and method are disclosed for protecting a database against deduction of confidential attribute values therein. A memory 160 is provided for storing the database and a processor 155 is provided for processing the database. Using the processor, the database is electronically partitioning into public attributes, containing nonconfidential attribute values, and private attributes, containing private attribute values. The processor is then used to electronically process the private attribute values to reduce any high correlation between public attribute values and private attribute values. Specifically, the processor can partition the database into safe tuples and unsafe tuples, which unsafe tuples have highly correlative public attribute values. The processor can then selectively combine the public attribute values of the tuples to camouflage such tuples from deduction of their private attribute values beyond a threshold level of uncertainty or remove such tuples from the database.

Abstract: The system comprises an apparatus for signalling to a party on hold that the hold initiating party is ready to continue conversation. As soon as the hold initiating party places the other party on hold, the party on hold activates the system which causes a pre-recorded message to be transmitted back to the hold initiating party. The pre-recorded message invites the hold initiating party to produce a DTMF signal tone. The DTMF signal activates a tone detector which turns off the message generator and produces an audio and visual signal to alert the party on hold. In this manner the party on hold is free to pursue normal activities until such time as the hold initiating party is ready to talk.