weak secure IDs
Zooko
zooko@zooko.com
Mon, 30 Sep 2002 05:53:15 -0400
Wei Dai wrote:
>
> The Chord project proposed using hashes of IP addresses as weak secure
> IDs, on the assumption that an attacker controls limited number of IP
> addresses. Here I propose an alternative weak secure ID scheme, on the
> assumption that the attacker has limited CPU power. This seems to be a
> safer assumption in the long run, since with IPv6 an attacker can easily
> have control over more IP addresses than the number of honest nodes.
Indeed, by cracking a box or bribing a sysadmin at BBN (or whoever owns their
IP address space now), you can *already* have more IP addresses than the
number of honest nodes.
I like your idea for incrementally more expensive IDs.
However I don't like the idea, in general, of allowing nodes to cause damage
but attempting to constrain the number of such nodes. Have you seen "The
Sybil Attack" by John Doceur? [1]
I don't at all agree with the conclusions, but he makes a good argument.
Regards,
Zooko
[1] http://www.cs.rice.edu/Conferences/IPTPS02/101.pdf