$Id: tunnel-alt.html,v 1.6 2005/01/25 00:46:22 jrandom Exp $
+$Id: tunnel-alt.html,v 1.7 2005/02/16 19:48:18 jrandom Exp $
1) Tunnel overview 2) Tunnel operation @@ -178,11 +178,14 @@ updates the IV by encrypting it with AES256/ECB using the participant's IV key, then forwards the tuple {nextTunnelId, nextIV, encryptedData} to the next hop.Duplicate message detection is handled by a decaying Bloom filter on message -IVs. Each router maintains a single Bloom filter to contain all of the IVs for -all of the tunnels it is participating in, modified to drop seen entries after -10-20 minutes (when the tunnels will have expired). The size of the bloom -filter and the parameters used are sufficient to more than saturate the router's -network connection with a negligible chance of false positive.
+IVs. Each router maintains a single Bloom filter to contain the XOR of the IV and +the first block of the message received for all of the tunnels it is participating +in, modified to drop seen entries after 10-20 minutes (when the tunnels will have +expired). The size of the bloom filter and the parameters used are sufficient to +more than saturate the router's network connection with a negligible chance of +false positive. The unique value fed into the Bloom filter is the XOR of the IV +and the first block so as to prevent nonsequential colluding peers in the tunnel +from tagging a message by resending it with the IV and first block switched.2.4) Endpoint processing