5

I know that a one-way function is informally a function that it's easy to compute but hard to invert.
If f(x) is a one way function the function $g(x) = x\oplus f(x)$ is a one-way function? My intuition is that it's but i not really sure.

Ran G.
  • 20,884
  • 3
  • 61
  • 117
dbonadiman
  • 517
  • 1
  • 4
  • 9

1 Answers1

6

Let $h$ be any one-way function, and define $f(x) = 0^{|x|} h(x)$. Note that $f$ is also one-way: it is easy to compute, and if you can invert $f$ you can invert $h$ (so since $h$ is hard to invert, so is $f$). But $g(x) = xh(x)$ is easy to invert.

Yuval Filmus
  • 280,205
  • 27
  • 317
  • 514