>It appears that this guarantee will not always hold. Specifically, if >two non-adjacent ASes conspire, and they are separated by a sequence of >ASes that sign path data that they have not verified, then the >conspiring ASes can violate the guarantee.
Agree with that. What do you think of the following two-update collusion scenario? -- > A --> B --> C --> D --> E A and D are colluding. B and C are signing without verifying. First update at time= t0: A signs and forwards an update normally (without any corruption). The update propagates via B and C to D. D receives it and stores it, but does not forward to E (or anyone). Second update at time= t1 (= t0 + delta): A sends an intentionally corrupted version of the update (signed), while keeping the same NLRI as before. B and C are still signing but not verifying. The update propagates via B and C to D. Now D replaces this corrupted update with the earlier clean one (received at t0), and propagates to E. The resulting update from D to E is valid. One can argue that there is violation of the guarantee (in Section 7.1) at time t1. The valid route propagated from D to E does not agree with the route that B or C forwarded (at time t1) for the NLRI in consideration. >I think this problem might be fixed if we modify the protocol to sign >all of the preceding signed data (rather than just the immediate, >previous signature). If we agree that the above two-update collusion scenario is something we care about, then it should be noted that this fix does not prevent it. Sriram _______________________________________________ sidr mailing list sidr@ietf.org https://www.ietf.org/mailman/listinfo/sidr
