From s7r at sky-ip.org Wed Oct 2 15:11:25 2019 From: s7r at sky-ip.org (s7r) Date: Wed, 2 Oct 2019 18:11:25 +0300 Subject: [Lightning-dev] [bitcoin-dev] Continuing the discussion about noinput / anyprevout In-Reply-To: <20191001155929.e2yznsetqesx2jxo@erisian.com.au> References: <87wodp7w9f.fsf@gmail.com> <20191001155929.e2yznsetqesx2jxo@erisian.com.au> Message-ID: <51d80db6-83d9-2473-d007-f3601c940f28@sky-ip.org> Anthony Towns via bitcoin-dev wrote: [SNIP] > > My thinking at the moment (subject to change!) is: > > * anyprevout signatures make the address you're signing for less safe, > which may cause you to lose funds when additional coins are sent to > the same address; this can be avoided if handled with care (or if you > don't care about losing funds in the event of address reuse) > It's not necessarily like this. Address re-use is many times OUTSIDE the control of the address owner. Say I give my address to a counterparty. They send me a transaction which I successfully spend. So far so good. After that, I have no control over that counterparty. If they decide to re-use that address, it does not mean I wanted to re-use it and it also does not mean that I don't care about those funds being lost. This could create a lot of problems in the industry and I think it should be avoided. Address re-use has been strongly discouraged ever since I can remember, and all (proper) wallet implementations try as hard as possible to enforce it, but it's not always possible. A counterparty that decides to re-use an address, either accidentally or not, is not under the control of the user who handed out the address in the first place. There are also a lot of use cases with P2SH addresses that are some smart contracts particularly designed to be re-used multiple times over time. My 2 cents are that this is not a good way to go. If you try to index the entire blockchain until now you'll see that address re-use is more common than we'd want it to be and there's no clear way to prevent this from further happening without hurting the economic interests of the users. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 488 bytes Desc: OpenPGP digital signature URL: