Anomos: Censhorship-resistant, Anonymous BitTorrent (Made by a HN'er)

Making a quick glance a the source code, it seems that this is basically fusing a simple mix-network into a torrent swarm. The clients have basic anonymity from each other (at the cost of a significant bandwidth cost due to the relaying) and the tracker acts as an oracle to hand out paths through the mix network so that peers can exchange blocks.

Here are some basic problems that come to mind:

* The tracker is a SPOF and making its role in the whole operation a distributed one at some future point will be _very_ difficult. If I want to "censor" this system I just DDoS the tracker and suddenly peers can't find each other.

* The tracker is using a simple weighted graph using Dijkstra for the shortest path from A to B. This is good for the swarm resources, but bad for attack resistence. If I want to probe the network and figure out who is who then I start taking out nodes I have connected to and see how the graph re-balances itself to adjust to this disruption. Instead of making the minimum path length a fixed number it should at least include a bit of randomness in the path length to increase the time it will take an attacker to completely map out the network in this fashion.

* The pipes are still not fixed bandwidth and always full. There is no cover traffic here, so in addition to the node by node mapping probe described previously a sufficiently powerful adversary can still black-box large chunks of the network and trivially match up the flows among nodes. Since the relaying has no delay at all this task is made significantly easier. When it comes to anonymity protocols you can trade bandwidth for security (full pipes with a chaffing/winnowing approach to pick real messages out of the cover traffic) or you can trade time for security (packet delay and re-ordering at relay nodes makes large-scale analysis harder), but you have to at least pick one.

Cute, but definitely not secure from TLAs, large network providers, or quite probably from a determined amateur with access to several widely dispersed boxes.

Now here is the real irony in all this: BitTorrent was a stripped down version of MojoNation that eliminated the centralized bandwidth accounting, crypto, peer chunk relaying, and persistence all in the name of moving bits quickly. Over the past six years everything but the persistence has slowly been layered back on through different efforts...