Maybe I'm missing something, but doesn't this mean the work has to be done by the client AND the server every time a challenge is issued? I think ideally you'd want work that was easy for the server and difficult for the server. And what is to stop being DDoS'd by clients that are challenged but neglect to perform the challenge?
Regardless, I think something like this is the way forward if one doesn't want to throw privacy entirely out the window.
Regardless, I think something like this is the way forward if one doesn't want to throw privacy entirely out the window.
client