A black fax is a prank fax transmission consisting of one or more pages entirely filled with a uniform black tone. The sender's intention is generally to use up as much of the recipient's fax ink, toner, or thermal paper as possible, thus costing the recipient money, as well as denying the recipient use of their own machine (similar to computer-based denial of service attacks). This is made easier because fax transmission protocols compress the solid black image very well, so a very short fax call can produce many pages.
The basic principle of a black fax can be extended to form a black fax attack. In this case, one or more sheets are fed halfway through the sender's fax machine and taped end to end, forming an endless loop that cycles through the machine. Not only can solid black be used, but also images that will repeat endlessly on the receiver's machine until its toner runs out.
Black faxes are similar (in both intention and implementation) to .
|
|