trapdoor

What if the room is circular, the table runs around the circumference, and you enter the room through a trapdoor in the center?

It describes a one-way function, but calls it a trapdoor function.

A backdoor — or trapdoor — is a secret vulnerability that can be exploited to break or circumvent supposedly secure systems.

Yes, that's essentially the difference between a one-way function and a trapdoor function.

While the equivalence between RSA and integer factorization is still an open question, the Rabin (exponent 2) trapdoor permutation is tightly equivalent to factoring.

Until one of the trucks opens a trapdoor and eats the drone!

I imagine there's a trapdoor available if you want to use floats anyway; actually, knowing Perl, I'm sure of it.

So looking at the discrete log problem vs a trapdoor function: Discrete log: for f(x) = y - Easy: given f and x find y.

All hermit crabs use shells, all trapdoor spiders lay traps.

Nash essentially predicts trapdoor functions and the P/NP gap...

And there's still the possibility that someone will find a trapdoor function that will be quantum resistant, so it isn't the end for all public key crypto.

I thought that a one-way function is only a trapdoor function if there exists the possibility of reversing it with an extra piece of information.

The wikipedia link[0] given seems to confirm that understanding: A trapdoor function is a function that is easy to compute in one direction, yet difficult to compute in the opposite direction (finding its inverse) without special information, called the "trapdoor".

(If you're okay with your denominators growing in an unbounded fashion, you can use the FatRat class instead.) The second "trapdoor" is that you can just explicitly work with Nums (ie C doubles).

Trapdoor: for f(x) = y - Easy: given f and y find x, given a secret, e.g.