Re: anti-spam WKBIs, Worsening google service reputation and abuse

It appears that Matthew Petach via NANOG <nanog@lists.nanog.org> said:

I think we should take a cue from cryptocurrencies, and have a "proof of stake" type of challenge for email messages sent out. The recipient machine doesn't accept a message until the sender has demonstrated they have put some skin in the game as well.

Dwork and Naor invented that in 1992. Clever idea, doesn't work in practice. https://www.wisdom.weizmann.ac.il/~naor/PAPERS/pvp.pdf R's, John