"Okay, you got me there." - it was not really intended as a trick - sorry for the wording.
As for the trivial hash - now I scrolled down the page on Wikipedia, indeed. I never thought of it this way. (That an identity function on an integer would deserve to be called a hash function :-)
The part that got me was the initial sentence about hash function converting "large, possibly variable amount of data" into a "small datum". As "large" and "small" are implied to be of different sizes, I glazed over a possibility of identity function there.
Oh, I didn't think you intended to trick me. Perhaps some context that'd help you understand my state of mind when I wrote that: while I may be a dev and hacker professionally and as a hobby, I went to university in mathematics specialising in number theory. I'm expected to know silly things like the difference between "one way function" and "trapdoor function", so it's a touch off-putting when I forget.
I know what you mean. For me it was: "Hm. he wrote that with a good confidence. Which part of my knowledge is wrong or incomplete ?" :-) Kind of the same feeling when the significant other garbage-collects a pen you put on the table just a few minutes ago.
As for the trivial hash - now I scrolled down the page on Wikipedia, indeed. I never thought of it this way. (That an identity function on an integer would deserve to be called a hash function :-)
The part that got me was the initial sentence about hash function converting "large, possibly variable amount of data" into a "small datum". As "large" and "small" are implied to be of different sizes, I glazed over a possibility of identity function there.
Thanks!