That is exactly what proof of work was invented to do. It’s the claim to fame of Adam Back, the current CEO of Blockstream. https://en.wikipedia.org/wiki/Hashc

That is exactly what proof of work was invented to do. It’s the claim to fame of Adam Back, the current CEO of Blockstream. https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash