On Friday, November 6, 2020 11:49 AM, Mike Schmidt via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:

Well I sure picked a bad couple weeks to volunteer to send a bunch of Bitcoin test transactions...

While I tested less than I would have liked, there are some notable results:

I think these results really show there is no reason to try to maintain the old-software-can-send-to-future-segwit-versions property, given that more than one not just didn't support it, but actually sent coins into a black hole.

Thus, I agree with Rusty that we should change the checksum for v1+ unconditionally. That also means that old senders are protected from the insertion issue (by failing, as we can guarantee that new-checksum addresses, even after a few errors, are invalid to old software).

I've sent another mail in this thread with details, but the TL;DR is that we should use the constant M=0x2bc830a3 rather than 0x3fffffff as previous suggested. More information on https://gist.github.com/sipa/14c248c288c3880a3b191f978a34508e.

Absent objections, I'll write up a BIP soon.

Cheers,

Pieter