<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Misbehaving addresses can have their connecting difficulty<br>
scaled up, which should make it uneconomic to try to DoS the usage of<br>
Tor exit nodes for connecting to Bitcoin.<br></blockquote><div><br></div><div>You can't solve DoS by requiring all clients to do complicated work, all that means is that weak clients (like users mobile phones and tablets) are successfully DoSd whereas the attackers botnet of stolen computers sit there solving PoWs.</div>
<div><br></div><div>The correct way to solve DoS is by having work prioritisation and queueing mechanisms, then finding ways to distinguish "good" clients from "bad" clients. Doing this whilst preserving privacy is hard. Long term the only way to solve it may be to require clients to present some kind of cookie during resource exhaustion events that prove they've been around for a while, thus allowing them to jump the queue.</div>
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