Free and open-source proof-of-work reactions library for Svelte web apps providing privacy-friendly way to stop reactions flooding

How POW captcha works

1. You generate a challenge which consists of a. difficulty, b. number of rounds
2. You generate a unique random string of characters for each round called id
3. User now has to find a hash so that hash(id + nonce) -> translated to binary (000111010101011) starts from difficulty number of consecutive zeroes by iterating nonce starting from 0 and until they find the hash
4. They send their solutions (nonces) back with the challenge signed by you (to retrieve parameters for captcha and keep this lib stateless)
5. All you have to do is verify their solutions by checking if hash(id + nonce) with their provided nonce -> translated to binary really starts from difficulty number of consecutive zeroes

Add progressively increasing difficulty with each subsequent request, and you get a pretty good stateless, privacy friendly rate limiter.

Not only this is a secure way of stopping flood but also a fair way for users to express their reaction. More reactions = more time to spend = those who appreciate the page's content more will send more reactions.