one-way function

A function f is a one-way functionMathworldPlanetmath if for any probabilistic, polynomial timeMathworldPlanetmath computable functionMathworldPlanetmath g and any polynomial function p there is m such that for all n>m:


where x has length n and all numbers of length n are equally likely.

That is, no probabilistic, polynomial time function can effectively compute f-1.

Note that, since f need not be injective, this is a stricter requirement than


since not only is g(f(x)) (almost always) not x, it is (almost always) no value such that f(g(f(x)))=f(x).

Title one-way function
Canonical name OnewayFunction
Date of creation 2013-03-22 13:03:14
Last modified on 2013-03-22 13:03:14
Owner Henry (455)
Last modified by Henry (455)
Numerical id 7
Author Henry (455)
Entry type Definition
Classification msc 68Q30
Synonym one way function
Synonym one-way
Synonym one way