An illegal number refers to a number that represents information that is illegal to possess, utter, propagate, or transmit in a legal jurisdiction. This includes any digital information that can be represented as a number. Examples of illegal numbers include classified information, trade secrets, and encryption keys that are claimed to be secret and whose possession or publication is considered illegal. The legal issues surrounding illegal numbers are distinct from copyright infringement. In some cases, images or executable programs can also be regarded as illegal numbers. There have been protests and controversies surrounding illegal numbers, including the creation of steganographic versions of the information and the banning of certain numbers in search engines and school districts. Illegal primes are a specific type of illegal number that is also prime. The concept of illegal numbers raises questions about the intersection of law, technology, and free speech.
| Signal | Change | 10y horizon | Driving force |
|---|---|---|---|
| Illegal number | Change in legality of certain numbers | Increased regulation and control over information | Protection of intellectual property rights |