Black Box

In computer-speak, black box is a euphemism for a program whose operational code is confidential, or otherwise unknown.

URLs:

The Black Box

The Black Box offers links to unspecified Web sites.

W3E References:

copyleft

The Free Software Foundation's copyleft policy of free distribution of source code is the antithesis of a black box policy.

Detail:

A black box is a device that produces a predictable output for a particular set of inputs, but whose internal workings are generally unknown. The classic example is the cockpit voice recorder in an airplane.

Computers used by investment firms to select stocks are referred to as "black boxes" as even the roughest outline of their software is a closely guarded secret. The inputs and output may be known, but the intermediate processes are proprietary secrets.

The more a system appears as a black box to someone else, the more secure it is from tampering.