Are you trying to claim that having the entire existing installed base not being able to validate the wtxids they get is acceptable? And that not being able to spend it, is acceptable? The customer support issues it is guaranteed to cost, is acceptable? That the lost reputation for backward compatibility and reliability, is acceptable?
fixing malleability, great!
But to be able to spend the wtxids dont you need to get the extra witness data? Is that data part of the segwit blockchain? If it is part of the segwit blockchain, isnt there the wtxid for each txid that wouldnt otherwise be needed?
What am I missing?
Segwit defines a new address type, but I don't think that will actually be implemented. Rather it will be using the witness program in p2sh addresses instead. A non-upgraded node will not have such addresses, they will still be using p2pkh addresses like we do now. If a segwit transaction were to be made which spent from a segwit output to an old p2pkh output, an old node would still be able to spend from it. The transaction would validate because the node sees it as an anyonecanspend input and the output is just like any p2pkh output in use right now. There is no need for the witness data to spend, it just cannot know whether the transaction it spends from was legitimate or not. Then it can still spend the p2pkh output normally as it does now.
To spend any received wtxid, you need to update to segwit chain, which is increased in size and includes the wtxid's for EVERY segwit tx, not just the merkle root. And this wtxid wouldnt be needed if we just hardforked to 2MB. So segwit as a space saver, actually loses space. Segwit as a softfork might be technically true, but it forces everyone to update to a sole sourced wallet or not be able to spend the coins received. And when they update, the wtxids are sitting there in their blockchain that wouldnt have been needed otherwise.
Well they aren't actually in the blockchain as we know it. It would essentially be like a secondary blockchain of all of the witness data. Either way, yes upgraded nodes would have to download 2 Mb of data.
So, for fixing malleability and other things, great. no problems with that. but to claim it is increasing tx capacity without a hardfork is disingenuous at best. Most people would like to be able to spend the bitcoins they get. If you can agree with that, then you must agree that they will need to load the segwit blockchain, which is bloated with wtxids that would not be needed in a simple 2MB hardfork
I know you must have some sort of marching orders to follow the party line, but please, let us not make silly claims like "wallets still function perfectly fine with the old system. They can still receive segwit transactions, they just can't spend from them" I dont want you to lose your credibility
Sorry, I actually spoke incorrectly there. I forgot about the whole address thing.
OK, so you agree that if segwit achieves the activation level, all nodes will have to update and download the 2MB of data, which contains 300kb+ of wtxids that otherwise wouldnt be needed in a straight 2MB hardfork.
so it is a total fail from a "increasing tx capacity without requiring a hardfork" point of view. Let us not quibble if it technically is a softfork or hardfork, the reality is users will have to update or not be able to spend. it looks like a hardfork, walks like a hardfork, quacks like a hardfork.
It sounds like it is possible to make it less of a problem, but it will be possible for segwit to be used to make unspendable payments to old nodes, so this creates an attack vector where the attacker simply sends to thousands of users some small amount of unspendable segwit wtxids. Once users get the bitcoins, they wont care about whether it is softfork or whatever, they will want to spend the bitcoins.
So, in the case where segwit is adopted, then all the nodes must update and get the full 2MB blocks that are bloated with needless wtxids. Now I just briefly looked at segwit details for the first time today, so maybe there is some super magic negative knowlege antimatter spacetime warping data compression that allows the segwit to actually save blockchain space. but calling the witness data not the blockchain since it is separate, again it becomes the type of stuff politicians do and not what technical guys should be doing. So if you are a politico, then fine, but I had always seen your posts as from an objective technical guy and was totally shocked at what you wrote. I am assuming the witness data is treated the same as the normal blockchain data, so it is in the same category and thus the statement that segwit is a total fail for increasing tx capacity without hardfork is fully justifed
Since segwit was started to fix malleability, maybe it should stick to that and not try to solve a problem it cannot solve. Officially claiming that it solves this is damaging to bitcoin's technical credibility and the other coins will take FULL advantage of this.
You cannot claim to be intelligent while advocating idiotic things, right?
James