Coincidentally I had thought of something similar to what Kalle posted about a kind of software only time-lock vault, and described the idea to a few people off-list. Re. Root incompatibility, if the key is deleted (as it must be) then a delegated signature can not be made that bypasses the CSV timeout restriction, so Root should not be incompatible with this. I think it would be disadvantageous to mark keys as Rootable vs not in a sighash sense, because then that is another privacy/fungibility loss eroding the uniformity advantage of Root when the delegate is not used.
One drawback is deleting keys may itself be a bit difficult to assure with HD wallet seeds setup-time backup model. As Anthony described I think, a simpler though less robust model would be to have a third party refuse to co-sign until a pre-arranged time, and this would have the advantage of not requiring two on-chain transactions. With bulletproofs and CT rangeproofs / general ECDL ZKPS there is the possibility to prove things about the private key, or hidden attributes of a public key in zero-knowledge. Kind of what we want is to place private key covenants, where we have to prove that they are met without disclosing them. For example there is a hidden CSV and it is met OR there is no hidden CSV so it is not applicable. Adam On 28 February 2018 at 23:30, Anthony Towns via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote: > On Wed, Feb 28, 2018 at 04:34:18AM +0000, アルム カールヨハン via bitcoin-dev wrote: >> 1. Graftroot probably breaks this (someone could just sign the >> time-locked output with a script that has no time-lock). > > Making the graftroot key be a 2-of-2 muSig with an independent third party > that commits to only signing CLTV scripts could avoid this. Making it > 3-of-3 or 5-of-5 could be even better if you can find multiple independent > services that will do it. > > Cheers, > aj > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
