acspring@knoware.nl (Andrew Spring):

...

Using a central node to coordinate the DC-net traffic requires that the participants trust that central node. If the central node is evil, A collation of N-1 nodes will always produce garbage; the whole set is needed for the message to fall out. Example ... A sends 14 - 5 = 9 to Central node B sends 5 - 11 = -6

Central nodes are not nice for various reasons, including the usual networking and security (trust) advantages of wide distribution. IAC a central node is not necessary; for example, if each node were to output to the next: B sends Anum XOR Brnd (XOR msg) to C where Brnd is B's random number, msg is B's message (if any) and Anum is the similarly generated output of A. This is much closer to the original DCNet _bit_ flipping - the first XOR checks for equality while the second commits the 'lie' In this case whatever number A gets from D is the output of the net. There are lots of interesting cryptographic sub-protocols to make too much trust unnecessary. I also believe that error-correction is best left to lower levels of the network - there's no need for a DC Net not to assume a reliable data channel. ----------------------------------------------------------------------------- Rishab Aiyer Ghosh "Clean the air! clean the sky! wash the wind! rishab@dxm.ernet.in take stone from stone and wash them..." rishab@arbornet.org Voice/Fax/Data +91 11 6853410 Voicemail +91 11 3760335 H 34C Saket, New Delhi 110017, INDIA