Because it would make no meaningful difference now, and if you are not going to check the history there are much more efficient things to do-- like not transfer it at all.
On Mon, Dec 18, 2017 at 8:32 AM, Kalle Rosenbaum via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote: > Dear list, > > I find it hard to understand why a full node that does initial block > download also must download witnesses if they are going to skip > verification anyway. If my full node skips signature verification for > blocks earlier than X, it seems the reasons for downloading the > witnesses for those blocks are: > > * to be able to send witnesses to other nodes. > > * to verify the witness root hash of the blocks > > I suppose that it's important to verify the witness root hash because > a bad peer may send me invalid witnesses during initial block > download, and if I don't verify that the witness root hash actually > commits to them, I will get banned by peers requesting the blocks from > me because I send them garbage. > > So both the reasons above (there may be more that I don't know about) > are actually the same reason: To be able to send witnesses to others > without getting banned. > > What if a node could chose not to download witnesses and thus chose to > send only witnessless blocks to peers. Let's call these nodes > witnessless nodes. Note that witnessless nodes are only witnessless > for blocks up to X. Everything after X is fully verified. > > Witnessless nodes would be able to sync faster because it needs to > download less data to calculate their UTXO set. They would therefore > more quickly be able to provide full service to SPV wallets and its > local wallets as well as serving blocks to other witnessless nodes > with same or higher assumevalid block. For witnessless nodes with > lower assumevalid they can serve at least some blocks. It could also > serve blocks to non-segwit nodes. > > Do witnessless nodes risk dividing the network in two parts, one > witnessless and one with full nodes, with few connections between the > parts? > > So basically, what are the reasons not to implement witnessless > nodes? > > Thank you, > /Kalle > > _______________________________________________ > 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
