CentralNotice From Wikipedia, the free encyclopedia Jump to navigation Jump to search Free Speech flag , from the HD DVD AACS case An illegal number is a number that represents information which is illegal to possess, utter, propagate, or otherwise transmit in some legal jurisdiction . Any piece of digital information is representable as a number; consequently, if communicating a specific set of information is illegal in some way, then the number may be illegal as well. [1] [2] [3] 1 Background 2 Flags and steganography 3 Other examples 4 See also 5 References 6 External links Background [ edit ] A number may represent some type of classified information or trade secret , legal to possess only by certain authorized persons. An AACS encryption key (09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0) that came to prominence in May 2007 is an example of a number...