Random number

Dice are an example of a mechanical hardware random number generator. When a cubical die is rolled, a random number from 1 to 6 is obtained.

A random number is generated by a random (stochastic) process such as throwing dice. Individual numbers cannot be predicted, but the likely result of generating a large quantity of numbers can be predicted by specific mathematical series and statistics.

Algorithms and implementations

Random numbers are frequently used in algorithms such as Knuth's 1964-developed algorithm ^[1] for shuffling lists. (popularly known as the Knuth shuffle or the Fisher–Yates shuffle , based on work they did in 1938).

In 1999, a new feature was added to the Pentium III: a hardware-based random number generator. ^{[2] [3]} It has been described as "several oscillators combine their outputs and that odd waveform is sampled asynchronously." ^[4] These numbers, however, were only 32 bit, at a time when export controls were on 56 bits and higher, so they were not state of the art. ^[5]

Common understanding

In common understanding, "1 2 3 4 5" is not as random as "3 5 2 1 4" and certainly not as random as "47 88 1 32 41" but "we can't say authoritavely that the first sequence is not random ... it could have been generated by chance." ^[6]

When a police officer claims to have done a "random .. door-to-door" search, there is a certain expectation that members of a jury will have. ^{[7] [8] [ example needed ]}

Real world consequences

Flaws in randomness have real-world consequences. ^{[9] [10]}

A 99.8% randomness was shown by researchers to negatively affect an estimated 27,000 customers of a large service ^[9] and that the problem was not limited to just that situation.^{[ clarification needed ]}

See also

• Algorithmically random sequence
• Quasi-random sequence
• Random number generation
• Random sequence
• Random variable
• Random variate
• Random real

References

1. Richard Durstenfeld (July 1964). "Algorithm 235: Random permutation". Communications of the ACM . 7 (7): 420. doi:10.1145/364520.364540.
2. Robert Moscowitz (July 12, 1999). "Privacy's Random Nature". Network Computing .
3. "Hardwiring Security". Wired . January 1999.
4. Terry Ritter (January 21, 1999). "The Pentium III RNG".
5. "Unpredictable Randomness Definition". IRISA.
6. Jonathan Knudson (January 1998). "Javatalk: Horseshoes, hand grenades and random numbers". Sun Server. pp. 16–17.
7. Tom Hays (April 16, 1995). "NYPD Bad Cop's Illegal Search Mars Career". Los Angeles Times .
8. A pre-compiled list of apartment numbers would be a violation thereof.
9. John Markoff (February 14, 2012). "Flaw Found in an Online Encryption Method". New York Times .
10. Reid Forgrave (May 3, 2018). "The man who cracked the lottery". New York Times .