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.
I don't know, so I can't agree or disagree. I couldn't find anything about how that would be serialized. I do agree that upgraded nodes would have to download all of the witness data though, whether they include the wtxids, I cannot say.
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.
I still say that it is a soft fork, albeit not entirely a soft fork but not a hard fork either. Let's agree to disagree.
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.
No, that is not possible. An old node would not know about the new witness program and how that works in an p2sh output. It would only know of p2pkh outputs that are meant for it, even if the witness program is just a p2pkh but segwit spendable only. The old node wouldn't know that it received such a payment so this attack wouldn't work.
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
Now that I think about it, I don't think the wtxids are included and that the witness data is included in a separate structure. If the witness data is requested, then I think (don't quote me on this) that it is just appended to its respective transaction in the block when it is sent. The wtxids are probably generated on the fly just like regular txids are generated on the fly as well. So in fact, it would be a 2 Mb increase but the "official" size of the block cuts out all of that witness data. If the block were to be requested normally as it is now, the witness data would not be included and the size of the block would be at most 1 Mb.
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.
I do agree that it should not have been marketed as a scalability solution but rather that it is for transaction malleability with a side effect of some scalability.