On Sun, Jul 20, 2025 at 9:35 PM Ethan Heilman <[email protected]> wrote:
> Does anyone remember why BIP-0173 added a special rule to make Witness > Versions legible in this way? It might be useful to document here for > future discussions on address encoding. > I'm not sure what you're referring to there -- there needed to be an _encoded_ version for the purpose of consensus rules. 1xxx addresses have one, for example (which results in them beginning with 1). The reason it's 5 bits is just to avoid needlessly inflating the length of addresses.. as additional versioning, if someday required could be achieved by additional words in the payload. There is a _human readable_ part, but that refers to the "bc" prefix identifying the currency/network, not any of the technical minutia about how the system works. The reason for the human readable part was that there has been instances of funds loss caused by fork coins / altcoins that copied bitcoin wholesale and used the same addresses and we'd hoped that a prefix that was easy to change an unambiguously associated with bitcoin would have a chance of reducing that risk in the future. or to restate: A recipient's script is fundamentally none of the sender's business (except for multiparty contracts or other special cases) -- and so generally we want the sender to be as oblivious of the details of the script as reasonably possible. If the sender has paid to the output the receiver has specified then they've done their part. Any further issues are the recipient's responsibility. If the sender hasn't-- e.g. say they took apart some address and made some custom script without the receivers consent, like turning a taproot pubkey into a legacy address-- then they haven't made a payment to the recipient and they still owe the recipient funds. But this also requires that the payment be on the right network, and while they could be informed outside of the address since it was a frequent cause of errors we thought it critical to embed it. The reason for making the embedding legible was primarily so that altcoins wouldn't just copy the prefix as they had frequently done with the version numbers. (and I believe so far this has proved to be successful, copies have changed the HRP) -- You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/CAAS2fgR%2BXccLeZqt0GXP%3Db-cu9ya%3D-pVZred_q6xGCrNKMLy9g%40mail.gmail.com.
