š
Original date posted:2015-11-19
š Original message:
With sighash_noinput, signers don't include their input's txid and index.
An even more powerful version would not even sign the pubkeyscript of the
input, which would allow some cool constructions.
In the case that there are multiple utxo outpoints which would be satisfied
by a single signature, miners can decide. It can be dangerous for this
reason if you re-use pubkeys. So don't! Especially in a multisig setting,
it seems unlikely to be a problem.
-Tadge
On Thu, Nov 19, 2015 at 11:15 AM, zaki at manian.org <zaki at manian.org> wrote:
> sighhash_noinput is the miner chooses which which utxo is consumed
> assuming there are multiple candidates variant of the idea?
>
>
>
> On Thu, Nov 19, 2015 at 11:12 AM, Tadge Dryja <tadge at lightning.network>
> wrote:
>
>> I've joked that BIP62 is the "whack-a-mole" BIP in that it addresses many
>> vectors for txid malleability, but maybe there are more. And more
>> importantly, it addresses 3rd party malleability. It's not helpful in the
>> context of lightning channel creation because ECDSA sigs are inherently
>> malleable. You can always re-sign the same message with a different
>> k-value and get a different signature.
>>
>> The functionality that's needed is to be able to reliably spend from
>> unconfirmed transactions. Segregated witness can accomplish that, but it
>> quite a large hard-fork change. sighash_noinput can also accomplish that:
>> as input txids are not signed, if they change, the spending transaction can
>> be modified while leaving counterparty signatures intact.
>>
>> I'm hoping to start a new "testnet-L" similar to testnet3, with this
>> sighash type so that we can test malleability mitigation out.
>>
>> (Oh also, hi mailing list, sorry I have not posted till now! But I will
>> start posting!)
>>
>> -Tadge
>>
>> On Thu, Nov 19, 2015 at 9:56 AM, Mark Friedenbach <mark at friedenbach.org>
>> wrote:
>>
>>> The basic idea of the soft-fork plan is very simple --- have the
>>> scriptPubKey be just the 20-byte hash of the redeem script. The scriptSig
>>> of the spending input is empty. The actual scriptSig, with the redeem
>>> script and signatures, is contained in a separate Merkle tree committed to
>>> elsewhere in the block (e.g. in the last output of the coinbase, or the
>>> last output of the last transaction).
>>>
>>> On Thu, Nov 19, 2015 at 7:31 AM, Greg Sanders <gsanders87 at gmail.com>
>>> wrote:
>>>
>>>> The hardfork variant is quite simple, if I understood it correctly. You
>>>> just stick the signatures in another parallel merkle tree. So if you don't
>>>> want to validate signatures, just don't download them, and validate
>>>> everything else. TXIDs don't use the signature at all. Nothing to malleate,
>>>> AFAIK. Not sure what the softfork plan is, but it will be a talk at Scaling
>>>> Bitcoin HK.
>>>>
>>>> On Thu, Nov 19, 2015 at 10:28 AM, Glenn Tarbox, PhD <glenn at tarbox.org>
>>>> wrote:
>>>>
>>>>>
>>>>> On Thu, Nov 19, 2015 at 4:33 AM, sickpig at gmail.com <sickpig at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hi Pierre
>>>>>>
>>>>>> you could start here
>>>>>>
>>>>>>
>>>>>> https://github.com/ElementsProject/elementsproject.github.io#segregated-witness
>>>>>>
>>>>>> https://people.xiph.org/~greg/blockstream.gmaxwell.elements.talk.060815.pdf
>>>>>> https://github.com/ElementsProject/elements
>>>>>
>>>>>
>>>>> There was a brief blip on Reddit:
>>>>>
>>>>>
>>>>> https://www.reddit.com/r/Bitcoin/comments/3ngtx5/could_the_segregated_witness_part_of_the/cwnthlh
>>>>>
>>>>> Its weird how little information there is on Segregated Witness. I'm
>>>>> guessing its a simple concept and those working on it (sipa / gmaxwell)
>>>>> haven't felt the need to write it up.
>>>>>
>>>>> That it "apparently" can be done with a soft fork similar to P2SH is
>>>>> good news... I guess...
>>>>>
>>>>>
>>>>> --
>>>>> Glenn H. Tarbox, PhD
>>>>> =]|[=
>>>>>
>>>>> _______________________________________________
>>>>> Lightning-dev mailing list
>>>>> Lightning-dev at lists.linuxfoundation.org
>>>>> https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev
>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> Lightning-dev mailing list
>>>> Lightning-dev at lists.linuxfoundation.org
>>>> https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev
>>>>
>>>>
>>>
>>> _______________________________________________
>>> Lightning-dev mailing list
>>> Lightning-dev at lists.linuxfoundation.org
>>> https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev
>>>
>>>
>>
>> _______________________________________________
>> Lightning-dev mailing list
>> Lightning-dev at lists.linuxfoundation.org
>> https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev
>>
>>
>
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Tadge Dryja [ARCHIVE] /
npub1v5ā¦6l74f
2023-06-09 12:45:09
in reply to nevent1qā¦2yws
Author Public Key
npub1v5856g02zudlkawxh4ut5kc6at8z5evt77lwxeaaudekq4dlfckst6l74fPublished at
2023-06-09 12:45:09Event JSON
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Original date posted:2015-11-19\nš Original message:\nWith sighash_noinput, signers don't include their input's txid and index.\nAn even more powerful version would not even sign the pubkeyscript of the\ninput, which would allow some cool constructions.\n\nIn the case that there are multiple utxo outpoints which would be satisfied\nby a single signature, miners can decide. It can be dangerous for this\nreason if you re-use pubkeys. So don't! Especially in a multisig setting,\nit seems unlikely to be a problem.\n\n-Tadge\n\nOn Thu, Nov 19, 2015 at 11:15 AM, zaki at manian.org \u003czaki at manian.org\u003e wrote:\n\n\u003e sighhash_noinput is the miner chooses which which utxo is consumed\n\u003e assuming there are multiple candidates variant of the idea?\n\u003e\n\u003e\n\u003e\n\u003e On Thu, Nov 19, 2015 at 11:12 AM, Tadge Dryja \u003ctadge at lightning.network\u003e\n\u003e wrote:\n\u003e\n\u003e\u003e I've joked that BIP62 is the \"whack-a-mole\" BIP in that it addresses many\n\u003e\u003e vectors for txid malleability, but maybe there are more. And more\n\u003e\u003e importantly, it addresses 3rd party malleability. It's not helpful in the\n\u003e\u003e context of lightning channel creation because ECDSA sigs are inherently\n\u003e\u003e malleable. You can always re-sign the same message with a different\n\u003e\u003e k-value and get a different signature.\n\u003e\u003e\n\u003e\u003e The functionality that's needed is to be able to reliably spend from\n\u003e\u003e unconfirmed transactions. Segregated witness can accomplish that, but it\n\u003e\u003e quite a large hard-fork change. sighash_noinput can also accomplish that:\n\u003e\u003e as input txids are not signed, if they change, the spending transaction can\n\u003e\u003e be modified while leaving counterparty signatures intact.\n\u003e\u003e\n\u003e\u003e I'm hoping to start a new \"testnet-L\" similar to testnet3, with this\n\u003e\u003e sighash type so that we can test malleability mitigation out.\n\u003e\u003e\n\u003e\u003e (Oh also, hi mailing list, sorry I have not posted till now! But I will\n\u003e\u003e start posting!)\n\u003e\u003e\n\u003e\u003e -Tadge\n\u003e\u003e\n\u003e\u003e On Thu, Nov 19, 2015 at 9:56 AM, Mark Friedenbach \u003cmark at friedenbach.org\u003e\n\u003e\u003e wrote:\n\u003e\u003e\n\u003e\u003e\u003e The basic idea of the soft-fork plan is very simple --- have the\n\u003e\u003e\u003e scriptPubKey be just the 20-byte hash of the redeem script. The scriptSig\n\u003e\u003e\u003e of the spending input is empty. The actual scriptSig, with the redeem\n\u003e\u003e\u003e script and signatures, is contained in a separate Merkle tree committed to\n\u003e\u003e\u003e elsewhere in the block (e.g. in the last output of the coinbase, or the\n\u003e\u003e\u003e last output of the last transaction).\n\u003e\u003e\u003e\n\u003e\u003e\u003e On Thu, Nov 19, 2015 at 7:31 AM, Greg Sanders \u003cgsanders87 at gmail.com\u003e\n\u003e\u003e\u003e wrote:\n\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e The hardfork variant is quite simple, if I understood it correctly. You\n\u003e\u003e\u003e\u003e just stick the signatures in another parallel merkle tree. So if you don't\n\u003e\u003e\u003e\u003e want to validate signatures, just don't download them, and validate\n\u003e\u003e\u003e\u003e everything else. TXIDs don't use the signature at all. Nothing to malleate,\n\u003e\u003e\u003e\u003e AFAIK. Not sure what the softfork plan is, but it will be a talk at Scaling\n\u003e\u003e\u003e\u003e Bitcoin HK.\n\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e On Thu, Nov 19, 2015 at 10:28 AM, Glenn Tarbox, PhD \u003cglenn at tarbox.org\u003e\n\u003e\u003e\u003e\u003e wrote:\n\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e On Thu, Nov 19, 2015 at 4:33 AM, sickpig at gmail.com \u003csickpig at gmail.com\u003e\n\u003e\u003e\u003e\u003e\u003e wrote:\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\u003e Hi Pierre\n\u003e\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\u003e you could start here\n\u003e\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\u003e https://github.com/ElementsProject/elementsproject.github.io#segregated-witness\n\u003e\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\u003e https://people.xiph.org/~greg/blockstream.gmaxwell.elements.talk.060815.pdf\n\u003e\u003e\u003e\u003e\u003e\u003e https://github.com/ElementsProject/elements\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e There was a brief blip on Reddit:\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e https://www.reddit.com/r/Bitcoin/comments/3ngtx5/could_the_segregated_witness_part_of_the/cwnthlh\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e Its weird how little information there is on Segregated Witness. I'm\n\u003e\u003e\u003e\u003e\u003e guessing its a simple concept and those working on it (sipa / gmaxwell)\n\u003e\u003e\u003e\u003e\u003e haven't felt the need to write it up.\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e That it \"apparently\" can be done with a soft fork similar to P2SH is\n\u003e\u003e\u003e\u003e\u003e good news... I guess...\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e --\n\u003e\u003e\u003e\u003e\u003e Glenn H. Tarbox, PhD\n\u003e\u003e\u003e\u003e\u003e =]|[=\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e _______________________________________________\n\u003e\u003e\u003e\u003e\u003e Lightning-dev mailing list\n\u003e\u003e\u003e\u003e\u003e Lightning-dev at lists.linuxfoundation.org\n\u003e\u003e\u003e\u003e\u003e https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e _______________________________________________\n\u003e\u003e\u003e\u003e Lightning-dev mailing list\n\u003e\u003e\u003e\u003e Lightning-dev at lists.linuxfoundation.org\n\u003e\u003e\u003e\u003e https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev\n\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\u003e\n\u003e\u003e\u003e\n\u003e\u003e\u003e _______________________________________________\n\u003e\u003e\u003e Lightning-dev mailing list\n\u003e\u003e\u003e Lightning-dev at lists.linuxfoundation.org\n\u003e\u003e\u003e https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev\n\u003e\u003e\u003e\n\u003e\u003e\u003e\n\u003e\u003e\n\u003e\u003e _______________________________________________\n\u003e\u003e Lightning-dev mailing list\n\u003e\u003e Lightning-dev at lists.linuxfoundation.org\n\u003e\u003e https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev\n\u003e\u003e\n\u003e\u003e\n\u003e\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20151119/e7a516bf/attachment.html\u003e",
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