21 ms·
As far as I know, this is a solved problem. http://www.wisdom.weizmann.ac.il/~naor/PAPERS/pvp_abs.html http://www.wisdom.weizmann.ac.il/~naor/PAPERS/pvp_abs.ht
by ethn 6y ago
As far as I know, this is a solved problem.
http://www.wisdom.weizmann.ac.il/~naor/PAPERS/pvp_abs.html http://www.wisdom.weizmann.ac.il/~naor/PAPERS/pvp_abs.html
An implementation of this is Hashcash which was used on UseNet very successfully: https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash