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Show HN: SHAllenge – Compete to get the lowest hash (shallenge.quirino.net)

submitted 1 year ago by bot@lemmy.smeargle.fans to c/hackernews@lemmy.smeargle.fans

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[–] lvxferre@mander.xyz 1 points 1 year ago* (last edited 1 year ago) (1 children)

OK... here's some dumb bash shit.

#!/bin/bash
i=0; z=0
while [[ $i -le 1000000000000 ]]; do
	o=$(echo "lvxferre/Hello+Fediverse+$i" | sha256sum)
	if [[ $o =~ ^($z) ]]; then
		echo "$i: $o"
		declare -g z="$z""0"
		fi
	if [[ $i == *000000 ]]; then
		echo "$(expr $i / 1000000)M combinations tried..."
		fi
	i=$[$i+1]
	done

Feel free to use it. Just make sure to change lvxferre/Hello+Fediverse+ to something else.

What it does: it generates the SHA256sum for strings starting with whatever you want, and ending in a number, between 0 and 10¹². Then if it finds one starting with "z" zeroes, it prints it alongside the number; then it looks for strings with an additional zero at the start. Each million tests it'll also print some output so you know that the script didn't freeze.

[–] lvxferre@mander.xyz 1 points 1 year ago

Update: so far my best string was lvxferre/Hello+Fediverse+2393194, yielding 0000006a 48...

I also did some simple optimisations of the code. Basically "the least you do, the faster it'll be".

i=7100000
while true; do
	o=$(echo "lvxferre/Hello+Fediverse+$i" | sha256sum)
	if [[ "$o" == 00000* ]]; then echo "$o $i"; fi
	if [[ "$i" == *00000 ]]; then echo "tried $i combinations..."; fi
	i=$[$i+1]
	done

Now it'll show results with more than five leading zeroes, and print a message every 100k tries (to resume later on).

My machine is a potato, mind you. I don't expect to get into the leaderboard. Still, I'm doing this as a bash exercise.