Quote from: user512 on June 18, 2019, 11:01:49 AM

Hi, everyone,
I have to ask you about SIGHASH_NOINPUT signature script. Means it that I can write a transaction its output can be rewritten in the future because the signature doesn't include output hash?
In original Eltoo whitepaper is written:

Quote

Notice that binding allows us to spend any output, without invalidating the signatures, as long as the output scripts and the input scripts match.

What means "output scripts and the input scripts match"? That means the next transaction must have the same output script?

0. The "no input" operation is being very very carefully thought out. Several ways to achieve it have been proposed, but so far everyone seems happy to continue to think about it some more. This is because it introduces a specific form of malleability (deliberately) to transactions, which could be misunderstood or abused. Note that this is not the same form of malleability that was removed when tightening signature rules, or with segregated witness, this is a different type of malleation than those.

so, the most important point imo is: whichever way "no input" gets introduced to Bitcoin script, it might not be in the form of any of the proposals that are around now. Wait and see, things could change (they have a couple times already).

1. It means the inputs can be unspecified when transactions are signed. That would be rejected by Bitcoin validation now. Some have suggested the amount should be specified.

2. all inputs and outputs are basic scripts, written in Bitcoin's own scripting language. What I think this probably means (without reading the original) is that the input script must be the same logic as the output script, but not necessarily the same money input needs to be used as the money output