📅 Original date posted:2017-08-17
📝 Original message:Some notes:
Hardforks like Bitcoin ABC without a malleability fix are very unlikely to
have payment channels, so the problem does not exist for those.
The designers of a hardfork which does have a malleability fix will
probably know about payment channels, so they can just build a replay
protection that allows the execution of old commitments. That needs some
kind of timestamping of commitments, which would have to be integrated in
the channel design. The easiest way would be to just write the time of
signing the commitment in the transaction and the replay protection accepts
old commitments, but rejects one's which were signed after the hardfork.
These timestamps can essentially be one bit (before or after a hardfork)
and if the replay protection in the hardfork only accepts old commitments
for something like a year, then it can be reused for more hardforks later
on. Maybe someone comes up with an interesting way of doing this without
using space.
Nevertheless hardforking while having channels open will always be a mess
as an open channel requires you to watch the blockchain. Anybody who is
just not aware of the hardfork or is updating his client a few days too
late, can get his money stolen by an old commitment transaction where he
forgets to retaliate on the new chain. As other's can likely figure out
your client version the risk of retaliation is not too big for an attacker.
2017-08-17 13:31 GMT+02:00 Bryan Bishop via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org>:
>
> ---------- Forwarded message ----------
> From: Christian Decker <decker.christian at gmail.com>
> Date: Thu, Aug 17, 2017 at 5:39 AM
> Subject: Re: [Lightning-dev] Lightning in the setting of blockchain
> hardforks
> To: Martin Schwarz <martin.schwarz at gmail.com>, lightning-dev at lists.
> linuxfoundation.org
>
>
> Hi Martin,
>
> this is the perfect venue to discuss this, welcome to the mailing list :-)
> Like you I think that using the first forked block as the forkchain's
> genesis block is the way to go, keeping the non-forked blockchain on the
> original genesis hash, to avoid disruption. It may become more difficult in
> the case one chain doesn't declare itself to be the forked chain.
>
> Even more interesting are channels that are open during the fork. In these
> cases we open a single channel, and will have to settle two. If no replay
> protection was implemented on the fork, then we can use the last commitment
> to close the channel (updates should be avoided since they now double any
> intended effect), if replay protection was implemented then commitments
> become invalid on the fork, and people will lose money.
>
> Fun times ahead :-)
>
> Cheers,
> Christian
>
> On Thu, Aug 17, 2017 at 10:53 AM Martin Schwarz <martin.schwarz at gmail.com>
> wrote:
>
>> Dear all,
>>
>> currently the chain_id allows to distinguish blockchains by the hash of
>> their genesis block.
>>
>> With hardforks branching off of the Bitcoin blockchain, how can Lightning
>> work on (or across)
>> distinct, permanent forks of a parent blockchain that share the same
>> genesis block?
>>
>> I suppose changing the definition of chain_id to the hash of the first
>> block of the new
>> branch and requiring replay and wipe-out protection should be sufficient.
>> But can we
>> relax these requirements? Are slow block times an issue? Can we use
>> Lightning to transact
>> on "almost frozen" block chains suffering from a sudden loss of hashpower?
>>
>> Has there been any previous discussion or study of Lightning in the
>> setting of hardforks?
>> (Is this the right place to discuss this? If not, where would be the
>> right place?)
>>
>> thanks,
>> Martin
>> _______________________________________________
>> 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
>
>
>
>
> --
> - Bryan
> http://heybryan.org/
> 1 512 203 0507 <(512)%20203-0507>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
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Conrad Burchert [ARCHIVE] /
npub1pc…nv5dy
2023-06-07 18:04:50
in reply to nevent1q…734r
Author Public Key
npub1pcdwyck6daahn2sv6hmxwpnrm3egsmf4jsgscz88as83c06c4rwq5nv5dyPublished at
2023-06-07 18:04:50Event JSON
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"content": "📅 Original date posted:2017-08-17\n📝 Original message:Some notes:\n\nHardforks like Bitcoin ABC without a malleability fix are very unlikely to\nhave payment channels, so the problem does not exist for those.\n\nThe designers of a hardfork which does have a malleability fix will\nprobably know about payment channels, so they can just build a replay\nprotection that allows the execution of old commitments. That needs some\nkind of timestamping of commitments, which would have to be integrated in\nthe channel design. The easiest way would be to just write the time of\nsigning the commitment in the transaction and the replay protection accepts\nold commitments, but rejects one's which were signed after the hardfork.\nThese timestamps can essentially be one bit (before or after a hardfork)\nand if the replay protection in the hardfork only accepts old commitments\nfor something like a year, then it can be reused for more hardforks later\non. Maybe someone comes up with an interesting way of doing this without\nusing space.\n\nNevertheless hardforking while having channels open will always be a mess\nas an open channel requires you to watch the blockchain. Anybody who is\njust not aware of the hardfork or is updating his client a few days too\nlate, can get his money stolen by an old commitment transaction where he\nforgets to retaliate on the new chain. As other's can likely figure out\nyour client version the risk of retaliation is not too big for an attacker.\n\n\n\n2017-08-17 13:31 GMT+02:00 Bryan Bishop via bitcoin-dev \u003c\nbitcoin-dev at lists.linuxfoundation.org\u003e:\n\n\u003e\n\u003e ---------- Forwarded message ----------\n\u003e From: Christian Decker \u003cdecker.christian at gmail.com\u003e\n\u003e Date: Thu, Aug 17, 2017 at 5:39 AM\n\u003e Subject: Re: [Lightning-dev] Lightning in the setting of blockchain\n\u003e hardforks\n\u003e To: Martin Schwarz \u003cmartin.schwarz at gmail.com\u003e, lightning-dev at lists.\n\u003e linuxfoundation.org\n\u003e\n\u003e\n\u003e Hi Martin,\n\u003e\n\u003e this is the perfect venue to discuss this, welcome to the mailing list :-)\n\u003e Like you I think that using the first forked block as the forkchain's\n\u003e genesis block is the way to go, keeping the non-forked blockchain on the\n\u003e original genesis hash, to avoid disruption. It may become more difficult in\n\u003e the case one chain doesn't declare itself to be the forked chain.\n\u003e\n\u003e Even more interesting are channels that are open during the fork. In these\n\u003e cases we open a single channel, and will have to settle two. If no replay\n\u003e protection was implemented on the fork, then we can use the last commitment\n\u003e to close the channel (updates should be avoided since they now double any\n\u003e intended effect), if replay protection was implemented then commitments\n\u003e become invalid on the fork, and people will lose money.\n\u003e\n\u003e Fun times ahead :-)\n\u003e\n\u003e Cheers,\n\u003e Christian\n\u003e\n\u003e On Thu, Aug 17, 2017 at 10:53 AM Martin Schwarz \u003cmartin.schwarz at gmail.com\u003e\n\u003e wrote:\n\u003e\n\u003e\u003e Dear all,\n\u003e\u003e\n\u003e\u003e currently the chain_id allows to distinguish blockchains by the hash of\n\u003e\u003e their genesis block.\n\u003e\u003e\n\u003e\u003e With hardforks branching off of the Bitcoin blockchain, how can Lightning\n\u003e\u003e work on (or across)\n\u003e\u003e distinct, permanent forks of a parent blockchain that share the same\n\u003e\u003e genesis block?\n\u003e\u003e\n\u003e\u003e I suppose changing the definition of chain_id to the hash of the first\n\u003e\u003e block of the new\n\u003e\u003e branch and requiring replay and wipe-out protection should be sufficient.\n\u003e\u003e But can we\n\u003e\u003e relax these requirements? Are slow block times an issue? Can we use\n\u003e\u003e Lightning to transact\n\u003e\u003e on \"almost frozen\" block chains suffering from a sudden loss of hashpower?\n\u003e\u003e\n\u003e\u003e Has there been any previous discussion or study of Lightning in the\n\u003e\u003e setting of hardforks?\n\u003e\u003e (Is this the right place to discuss this? If not, where would be the\n\u003e\u003e right place?)\n\u003e\u003e\n\u003e\u003e thanks,\n\u003e\u003e Martin\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\n\u003e _______________________________________________\n\u003e Lightning-dev mailing list\n\u003e Lightning-dev at lists.linuxfoundation.org\n\u003e https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev\n\u003e\n\u003e\n\u003e\n\u003e\n\u003e --\n\u003e - Bryan\n\u003e http://heybryan.org/\n\u003e 1 512 203 0507 \u003c(512)%20203-0507\u003e\n\u003e\n\u003e _______________________________________________\n\u003e bitcoin-dev mailing list\n\u003e bitcoin-dev at lists.linuxfoundation.org\n\u003e https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev\n\u003e\n\u003e\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20170817/af84de89/attachment.html\u003e",
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