ICANN are currently requesting public comments on restarting the root DNSSEC KSK rollover. I thought I didn’t have anything particularly useful to say, but when I was asked to contribute a comment I found that I had more opinions than I realised! So I sent in some thoughts which you can see on the KSK public comments list and which are duplicated below.
The ongoing work on trust anchor telemetry and KSK sentinel might be useful for making an informed decision, but there is the risk of getting into the trap that there is never enough data. It would be bad to delay again and again for just one more experiment. KSK sentinel might provide better data than trust anchor telemetry, but I fear it is too late for this rollover, and it may never be deployed by the problem sites that cause concern. So maybe the quest for data is not absolutely crucial.
I increasingly think RFC 5011 is insufficient and not actually very helpful. It was implemented rather late and it seems many deployments don’t use it at all. It only solves the easy problem of online rollovers: it doesn’t help with bootstrapping or recovery.
RFC 7958 moves the problem around rather than solving it. It suggests that we can treat personal PGP keys or self-signed X.509 keys with unclear provenance as more trusted than the root key, with all its elaborate documentation, protections, and ceremonial. It adds more points of failure, whereas a proper solution should disperse trust.
I think the best short term option is to put more emphasis on using software updates for distributing the root trust anchors. The software is already trusted, so using it for key distribution doesn’t introduce a new point of failure. Most vendors have a plausible security update process. Software updates can solve the same problems as RFC 5011, in a straight-forward and familiar way. Across the ecosystem as a whole it disperses trust amongst the vendors.
Longer term I would like a mechanism that addresses bootstrap and recovery (because you can’t get your software update without DNS) but that is not doable before the rollover later this year.