Hi, Since the BIP is already in proposed status, I think that we should specify the non-witness utxo to just be "witness or non-witness" serialization. This maintains compatibility with things that have already implemented but also maintains the forwards compatibility that is needed.
Andrew ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On August 13, 2018 11:56 AM, Pieter Wuille via bitcoin-dev <email@example.com> wrote: > Hello all, > > BIP174 currently specifies that non-witness UTXOs (the transactions > being spent by non-witness inputs) should be serialized in network > format. > > I believe there are two issues with this. > > 1. Even in case the transaction whose output being spent itself has a > witness, this witness is immaterial to PSBT. It's only there to be > able to verify the txid commits to the output/amount being spent, > which can be done without witness. > > 2. "Network format" is a bit ambiguous. We can imagine a future > softfork that introduces a new type of witness. Network format could > be interpreted as including that new witness type, which is clearly > unnecessary (by the above argument), and would gratuitously break > compatibility with existing signers if implemented pedantically. > > So my suggestion is to update the specification to state that > non-witness UTXOs must be serialized without witness. If it's too late > for that, it should instead be updated to explicitly specify with or > witnout witness, but it's safe to drop the witness. > > Opinions? > > Cheers, > > -- > Pieter > > > bitcoin-dev mailing list > firstname.lastname@example.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev _______________________________________________ bitcoin-dev mailing list email@example.com https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev