A one-way function `f:X→Y`

is a function
where it is easy to compute `y∈Y`

for a given `x∈X`

such that `f(x)=y`

but it is computationally infeasible to compute `x∈X`

for a given `y∈Y`

such that `f(x)=y`

A. Menzes, P. van Oorschot, and S. Vanstone, *Handbook of Applied Cryptography.* CRC Press, 1996.

Copyright © 2014 Barry Watson. All rights reserved.