Cross-signing followup


So that’s old news indeed. The announcement is about end leaf certificates with a ECC public/private keypair. Not about an ECC intermediate.

ISRG Root X1 added to Firefox for next release

We don’t have a firm timeline yet for an ECC intermediate. It’s something we’d like to do, but is currently unscheduled.


What are you talking about? Did you REALLY bring up the ISRG Root X1 to sign X3 and X4 intermediates, but couldn’t also generate and sign ECDSA intermediates in that same ceremony? You previously said that in a ceremony you eould do both. And anyway, why wasn’t this ceremony described anywhere? I learnt from it by the above link on


I wouldn’t put it that aggressively, there were probably good reasons not to generate and sign ECC intermediates, but I agree it’s a missed chance.


Having an ECDSA intermediate on hand while the CA software doesn’t support issuance from multiple intermediates would not be particularly useful. Additionally, an ISRG-signed ECDSA intermediate would not be all that practical to use yet, you’d want that signed by IdenTrust as well. In other words, no reason to rush that particular step when there’s plenty of other things to do first anyway.


Generating the public/private key pair of the intermediates would be the first step. Having those around is the most important: getting the cert signed by IdenTrust is quite trivial (relatively) I assume: if this step uses a CSR, you can generate that one too and get it signed sometime later. (I’m not actually sure how cross-signing works technically :stuck_out_tongue:)
It was perfectly possible to get the X3 and X4 cross-signed, so I assume it’s not that of a hassle for ECDSA intermediates.


My problem was initially that there is no public announcement. But this is really a big issue because they had already generated it within the ISRG X1 so it would now soon in all trust stores already. Now we need to wait and hope that IdenTrust has such ECC Root already propagated in all relevant trust stores.


Yep! It turns out bringing the root online (and having all the necessary people present) is only one part of the work involved in signing new intermediates. The other part is writing, and testing, the detailed script of the ceremony, and preparing all the relevant software. We had an urgent need to generate the LEAX3(ISRG Root X1) and LEAX4(ISRG Root X1) signatures due to root program requirements, and decided that it was more urgent to get those done sooner, rather than to delay the ceremony and do the extra work for an EC root and intermediates.


Could an EC root get some kind of “fast track” into root programs, because the RSA equivalent is already accepted?


My understanding is that, yes, new roots from existing CAs tend to be accepted more quickly into root programs, but that is not a guarantee.


I also hope that this time the expected Time to Arrive from the Upcoming Features in EC isn’t going to change again…


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