On Mon, Sep 05, 2005 at 03:18:08PM -0700, Nathan Johnson wrote: > Structure of Subscription Graph > > You wondered if the subscription could be a tree. I don't think so, but it > can > be directional and perhaps without loops, which may be about as good as a > tree.
It can be a tree. With occasional dangling loops. > You can make it this way by having a subscription request have a unique ID so > that multiple subscriptions to the same data will each have their own ID on > the > request. Then a subscription request will not join to itself if it collides > with itself, but will join and discontinue if it collides with another > subscription graph. A malicious attacker may be able to create cycles however > by repeating the subscription ID. Well, technically, but then you need to have every single subscription go through every node on the chain. Which is very bad. > > Vulnerability of Listen/Subscribe > > The main reason we weren't doing this before was for fear of an attacker > putting > a listen/subscribe on every node. Is this still as much an issue? That's related to passive requests mostly. To pull it off in any case the attacker would need to be connected to (almost?) any node, in which case you're screwed anyway, and which is very hard on a darknet. > > Properties of the subscription 'stream' > > When I encounter "data stream" it usually has the properties of: > guaranteed ordered delivery; Packets with sequence numbers. > maybe guaranteed delivery; Best effort based on above; caches on each node in the tree. > no packetizing, dissolution of packet boundaries in the stream. Even TCP packetises. It has to. > I think that the freenet architecture is not conducive to supporting any of > these properties. Supporting them would be undesirable and ineffecient. Are > you intending to support these properties? Do you think it's a good idea? It's better than polling a series of SSKs. It lets us do efficient real time delivery. In particular it lets us do IRC. In future it could let us do audio streams (which are also packetised btw ;) ) etc. -- Matthew J Toseland - toad at amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: Digital signature URL: <https://emu.freenetproject.org/pipermail/tech/attachments/20050906/3d44f2fd/attachment.pgp>
