How a weapon against war became a weapon against the web
theverge.com
theverge.com
Maybe I should have mentioned one other condition. The network must be distributed and consist of nodes with symmetric bandwidth. If you have symmetric bandwidth you can upload as fast as you download and thus on average the network won't need altruistic nodes to saturate everyone's downlink.
We could go even further and demand ISP-local source-specific multicast, then you would have massive bandwidth multiplication for uploaders, making it trivial to replicate popular content. Alas, that seems to be a pipe dream.
No, I'm saying that if someone is trying to DDoS your torrent, the bandwidth doesn't scale with the number of downloaders because all the malicious nodes are using download bandwidth but (deliberately) not providing upload bandwidth. I was playing a bit fast and loose with the term "leecher" (I meant someone downloading but <i>not uploading at all</i>, as opposed to active participants in the swarm), but I thought that was understood. Even if you had a system where people were prioritized based on how much they were sharing, there are a lot of ways to get around that protocol with a big enough botnet.
Don't get me wrong, the built-in scaling features of things like torrents are great, I'm just saying I don't see an easy way for it to solve DDoS because it relies on cooperation from the participants.
If you make your content distributed it can be mirrored by many more nodes than are needed to satisfy demand, removing some of the asymmetry while also making it more difficult for the attacker to pick his targets. Note that p2p networks can also respond to demand. E.g. in torrents clients don't seed all the content they have all the time, they first check statistics which swarms could use the bandwidth most. So if there were some content under attack by fake downloaders it would look like a swarm in need of extra bandwidth and thus more real nodes would join it to serve content, thus making the attack more costly.
> Even if you had a system where people were prioritized based on how much they were sharing, there are a lot of ways to get around that protocol with a big enough botnet.
With a big enough botnet you can also take out any ddos protection service.
Or to be accurate, your client is giving priority (for you to upload) to people who are uploading contents to you.
And avoiding being throtted how?