User talk:Qntm

edit at trapdoor function

I'm confused about your edit at trapdoor function. The entire lead seems to be written based on the narrative that $t$, the secret information that allows computing $x$ from $f(x)$ and $t$, is called the trapdoor. If not, then what is the trapdoor? Can you clarify? Maybe we can converge on a more coherent rewrite than the current version. Caleb Stanford (talk) 21:22, 6 April 2022 (UTC)[reply]

OK so let's make sure we understand the trapdoor metaphor for a trapdoor function. Falling through a trapdoor is easy, but getting back up is very difficult. Falling through the trapdoor represents applying the trapdoor function to an initial value to get a result, and getting back up represents reversing that process to turn the result back into the initial value.

Reversing the trapdoor function is made easier if you have a particular piece of information to hand. In the real-world trapdoor metaphor, getting back up is made easier if you have a particular useful tool which helps you get back up. This useful tool is a ladder. Not, as the article appears to think, the trapdoor itself. If you've fallen through the trapdoor, how is the trapdoor any use in climbing back up? After falling through the trapdoor, you can't even reach the trapdoor. The entire metaphor makes no sense that way.

In the secondary metaphor of a padlock and key, again, the padlock's key represents a ladder. Qntm (talk) 00:21, 8 April 2022 (UTC)[reply]

Thank you for the answer and I totally agree, that makes more sense metaphorically! However, the entire article seems to be written referring to the secret value t as "trapdoor". My hunch based on the article is that this is how the term may be used in the literature. Two possible solutions:

1. Add a clarifying sentence somewhere stating that although the key is not really a trapdoor in the metaphor, it is often referred to as a trapdoor

2. Comprehensively update the article with better terminology

In case (2), which requires a substantial rewrite, we need to be clear on the terminology in the literature first -- I don't do cryptography stuff so I don't know the area. It would be best to use the same terminology as what's standard, or if not, to clearly state how we differ. Caleb Stanford (talk) 14:12, 8 April 2022 (UTC)[reply]