Level 1: All our directly connected nodes get credibility of 100%. Level 2: A node's credibility is simply the number of our directly connected nodes which are connected to it, divided by the total number of our directly connected nodes. For example, we have 6 nodes, E is connected to 3 of them, so it gets a credibility of 50%. Level 3: The sum of the credibility of each level 2 node it is connected to, divided by the number of level 2 nodes. So if F is only connected to E, and there are 12 level 2 nodes, it gets 50%/12. Better: divide by the total credibility:
At level 1, we have 6 nodes with 100% cred. At level 2, we have 18 nodes with total cred of 10. At level 3, for example, we have a node connected to 3 level 2 nodes, with a total credibility of 2. This gives it 20% credibility. How to combine credibility for nodes which connect at multiple levels? If A is connected to a level 2 node at cred 50%, and a level 3 node at cred 20%, and the two are independant, in other words, the level 3 node is not connected to the level 2 node, we can simply add the fractions: 50% / 10 + 20% / total 3rd level cred. If A is connected to a level 2 node at cred 50%, and a level 3 node at 20%, and the level 3 node is connected to 3 level 2 nodes including the mentioned one, we have two options: a) We ignore the level 3 connection. b) We factor out the level 2 connection when calculating the cred proportion for the level 3 node. Okay, what is the point of all this? It lets us select nodes which are reasonably likely to be real. This is very VERY useful for premix routing, although obviously there are statistical issues; we need to create a cell amongst which any node is equally likely to send a request through any other node, or there are statistical attacks. But we can use this sort of reasoning to assure integrity within the cell. It is also useful for any collaborative network activities such as estimating the size of the network, or the distribution of link lengths. -- 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/20060128/7f98bc82/attachment.pgp>
