Randomness is a mathematical notion that is used in many modern life area. It is use in the form of a random sequence in geolocalisation system, automatic gambling games, cryptology and others. The mathematical definition of a ransom sequence is still going under discussions, but certain properties have been demonstrated and an agreement was found around three approaches:

  • The frequency, measure-theoretic approach (Martin-Löf, 1966) (No random sequence should have exceptional regularity or be effectively testable).
  • The complexity, compressibility approach (Chaitin 1975) (A random sequence should be incompressible)
  • The predictability approach (Schnorr 1971) (A random sequence should be unpredictable)

From there, no random sequence can be generated from an algorithm. If so, the sequence will be considered as pseudorandom and its level of randomness will depend from the context.

The sources of randomness can be separated into three categories: unpredictable (dices, random sorting,…), physical (radioactivity, electromagnetism,…), computational (mix of physic and algorithms).

Another potential way is the human brain. Human decision have been showed to be influenced by bias, but few studies have been made on the human capacity to produce a random sequence. To do so, the experience will ask the user to write a sequence of numbers and to play with it, the aim being to fool the computer.