In cryptography, a statistical distribution of characters matching what a human would produce while typing "random" keystrokes. Unlike a uniform distribution, certain characters and character combinations are much more likely than others; for example, the conditional probability of a character c₂ given the previous character c₁ is higher if c₁ and c₂ are adjacent on the keyboard and typed with the same hand.

The string asdfasdf is an example of a highly probable string in a typewriter random distribution for a U.S. or English keyboard.