* [bitcoin-dev] A BIP proposal for transactions that are 'cancellable'
@ 2018-09-06 9:19 Alejandro Ranchal Pedrosa
2018-09-06 13:31 ` Matt Corallo
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: Alejandro Ranchal Pedrosa @ 2018-09-06 9:19 UTC (permalink / raw)
To: bitcoin-dev; +Cc: TUCCI Sara, Önder GÜRCAN
[-- Attachment #1: Type: text/plain, Size: 1439 bytes --]
Hello everyone,
We would like to propose a new BIP to extend OP_CSV (and/or OP_CLTV) in
order for these to allow and interpret negative values. This way,
taking the example shown in BIP 112:
HASH160 <revokehash> EQUAL
IF
<Bob's pubkey>
ELSE
"24h" CHECKSEQUENCEVERIFY DROP
<Alice's pubkey>
ENDIF
CHECKSIG
that gives ownership only to Bob for the first 24 hours and then to
whichever spends first, we basically propose using the negative bit value:
HASH160 <revokehash> EQUAL
IF
<Bob's pubkey>
ELSE
"-24h" CHECKSEQUENCEVERIFY DROP
<Alice's pubkey>
ENDIF
CHECKSIG
meaning that both would have ownership for the first 24 hours, but
after that only Bob would own such coins. Its implementation should
not be too tedious, and in fact it simply implies considering negative
values that are at the moment discarded as for the specification of
BIP-112, leaving the sign bit unused.
This, we argue, an increase the fairness of the users, and can at times
be more cost-effective for users to do rather than trying a Replace-By-Fee
transaction, should they want to modify such payment.
We would like to have a discussion about this before proposing the
BIP, for which we are preparing the text.
You can find our paper discussing it here:
https://hal-cea.archives-ouvertes.fr/cea-01867357 (find attached as well)
Best,
--
Alejandro Ranchal Pedrosa, Önder Gürcan and Sara Tucci-Piergiovanni
[-- Attachment #2: Gurcan2018. On Cancellation of Transactions in Bitcoin-like Blockchains.pdf --]
[-- Type: application/pdf, Size: 785408 bytes --]
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 9:19 [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' Alejandro Ranchal Pedrosa @ 2018-09-06 13:31 ` Matt Corallo [not found] ` <CABaiX-2L9oVdta=aRH91uE=iPRv4cX6zU0=+oF+2oWqnu=64YQ@mail.gmail.com> 2018-09-06 15:16 ` Gregory Maxwell 2018-09-06 16:14 ` vizeet srivastava 2 siblings, 1 reply; 11+ messages in thread From: Matt Corallo @ 2018-09-06 13:31 UTC (permalink / raw) To: Alejandro Ranchal Pedrosa, Bitcoin Protocol Discussion, Alejandro Ranchal Pedrosa via bitcoin-dev, bitcoin-dev Cc: TUCCI Sara, Önder GÜRCAN [-- Attachment #1: Type: text/plain, Size: 1921 bytes --] I think a simple approach to what you want to accomplish is to simply have a multisig option with a locktime pre-signed transaction which is broadcastable at the 24h mark and has different spendability. This avoids introducing reorg-induced invalidity. On September 6, 2018 9:19:24 AM UTC, Alejandro Ranchal Pedrosa via bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org> wrote: >Hello everyone, > >We would like to propose a new BIP to extend OP_CSV (and/or OP_CLTV) in >order for these to allow and interpret negative values. This way, >taking the example shown in BIP 112: > >HASH160 <revokehash> EQUAL >IF > <Bob's pubkey> >ELSE > "24h" CHECKSEQUENCEVERIFY DROP > <Alice's pubkey> >ENDIF >CHECKSIG > >that gives ownership only to Bob for the first 24 hours and then to >whichever spends first, we basically propose using the negative bit >value: > >HASH160 <revokehash> EQUAL >IF > <Bob's pubkey> >ELSE > "-24h" CHECKSEQUENCEVERIFY DROP > <Alice's pubkey> >ENDIF >CHECKSIG > >meaning that both would have ownership for the first 24 hours, but >after that only Bob would own such coins. Its implementation should >not be too tedious, and in fact it simply implies considering negative >values that are at the moment discarded as for the specification of >BIP-112, leaving the sign bit unused. > >This, we argue, an increase the fairness of the users, and can at times >be more cost-effective for users to do rather than trying a >Replace-By-Fee >transaction, should they want to modify such payment. > >We would like to have a discussion about this before proposing the >BIP, for which we are preparing the text. > >You can find our paper discussing it here: >https://hal-cea.archives-ouvertes.fr/cea-01867357 (find attached as >well) > >Best, > >-- >Alejandro Ranchal Pedrosa, Önder Gürcan and Sara Tucci-Piergiovanni [-- Attachment #2: Type: text/html, Size: 2298 bytes --] ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <CABaiX-2L9oVdta=aRH91uE=iPRv4cX6zU0=+oF+2oWqnu=64YQ@mail.gmail.com>]
* [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' [not found] ` <CABaiX-2L9oVdta=aRH91uE=iPRv4cX6zU0=+oF+2oWqnu=64YQ@mail.gmail.com> @ 2018-09-06 16:33 ` Matt Corallo 2018-09-07 7:07 ` Alejandro Ranchal Pedrosa 0 siblings, 1 reply; 11+ messages in thread From: Matt Corallo @ 2018-09-06 16:33 UTC (permalink / raw) To: Alejandro Ranchal Pedrosa; +Cc: Bitcoin Dev I think you misunderstood my proposal. What you'd do is the transaction is spendable by either Bob OR (Bob AND Alice) and before broadcast/during construction/whatever sign a new transaction that spends it and is only spendable by Alice, but is timelocked for 24 hours. At the 24h mark, Alice broadcasts the transaction and once it is confirmed only Alice can claim the money. On 09/06/18 10:59, Alejandro Ranchal Pedrosa wrote: > Dear Matt, > > Notice that what you suggest has some substantial differences. With your > suggestion of a multisig option with a 24h timelock, once you give Alice > the chance to spend that UTXO without a negative timelock (as we argue), > by means of, say, a transaction that she can use, you cannot enforce > that this is not used by Alice after the 24hs. Perhaps it is possible, > tweaking the Lightning Channel design of Breach Remedy txs, to penalize > Alice if she does this, but this requires Bob to check the Blockchain in > case he needs to publish a proof-of-fraud, think of adding extra funds > to the transaction to account for penalization, etc. > > Feel free to correct me if I got it wrong in your email. > > Best, > Alejandro. > > > On Thu, Sep 6, 2018 at 3:32 PM Matt Corallo <lf-lists@mattcorallo•com > <mailto:lf-lists@mattcorallo•com>> wrote: > > I think a simple approach to what you want to accomplish is to > simply have a multisig option with a locktime pre-signed transaction > which is broadcastable at the 24h mark and has different > spendability. This avoids introducing reorg-induced invalidity. > > On September 6, 2018 9:19:24 AM UTC, Alejandro Ranchal Pedrosa via > bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org > <mailto:bitcoin-dev@lists•linuxfoundation.org>> wrote: > > Hello everyone, > > We would like to propose a new BIP to extend OP_CSV (and/or OP_CLTV) in > order for these to allow and interpret negative values. This way, > taking the example shown in BIP 112: > > HASH160 <revokehash> EQUAL > IF > <Bob's pubkey> > ELSE > "24h" CHECKSEQUENCEVERIFY DROP > <Alice's pubkey> > ENDIF > CHECKSIG > > that gives ownership only to Bob for the first 24 hours and then to > whichever spends first, we basically propose using the negative bit value: > > HASH160 <revokehash> EQUAL > IF > <Bob's pubkey> > ELSE > "-24h" CHECKSEQUENCEVERIFY DROP > <Alice's pubkey> > ENDIF > CHECKSIG > > meaning that both would have ownership for the first 24 hours, but > after that only Bob would own such coins. Its implementation should > not be too tedious, and in fact it simply implies considering negative > values that are at the moment discarded as for the specification of > BIP-112, leaving the sign bit unused. > > This, we argue, an increase the fairness of the users, and can at times > be more cost-effective for users to do rather than trying a Replace-By-Fee > transaction, should they want to modify such payment. > > We would like to have a discussion about this before proposing the > BIP, for which we are preparing the text. > > You can find our paper discussing it here: > https://hal-cea.archives-ouvertes.fr/cea-01867357 (find attached as well) > > Best, > ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 16:33 ` Matt Corallo @ 2018-09-07 7:07 ` Alejandro Ranchal Pedrosa 0 siblings, 0 replies; 11+ messages in thread From: Alejandro Ranchal Pedrosa @ 2018-09-07 7:07 UTC (permalink / raw) To: Matt Corallo; +Cc: Bitcoin Dev Yes I agree with what you mean but this requires Alice to broadcast an additional transaction. Also, Alice is supposed to be able to 'cancel' the transaction in the first 24hours, not after them. Best, Alejandro. On 9/6/18 6:33 PM, Matt Corallo wrote: > I think you misunderstood my proposal. What you'd do is the transaction > is spendable by either Bob OR (Bob AND Alice) and before > broadcast/during construction/whatever sign a new transaction that > spends it and is only spendable by Alice, but is timelocked for 24 > hours. At the 24h mark, Alice broadcasts the transaction and once it is > confirmed only Alice can claim the money. > > On 09/06/18 10:59, Alejandro Ranchal Pedrosa wrote: >> Dear Matt, >> >> Notice that what you suggest has some substantial differences. With your >> suggestion of a multisig option with a 24h timelock, once you give Alice >> the chance to spend that UTXO without a negative timelock (as we argue), >> by means of, say, a transaction that she can use, you cannot enforce >> that this is not used by Alice after the 24hs. Perhaps it is possible, >> tweaking the Lightning Channel design of Breach Remedy txs, to penalize >> Alice if she does this, but this requires Bob to check the Blockchain in >> case he needs to publish a proof-of-fraud, think of adding extra funds >> to the transaction to account for penalization, etc. >> >> Feel free to correct me if I got it wrong in your email. >> >> Best, >> Alejandro. >> >> >> On Thu, Sep 6, 2018 at 3:32 PM Matt Corallo <lf-lists@mattcorallo•com >> <mailto:lf-lists@mattcorallo•com>> wrote: >> >> I think a simple approach to what you want to accomplish is to >> simply have a multisig option with a locktime pre-signed transaction >> which is broadcastable at the 24h mark and has different >> spendability. This avoids introducing reorg-induced invalidity. >> >> On September 6, 2018 9:19:24 AM UTC, Alejandro Ranchal Pedrosa via >> bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org >> <mailto:bitcoin-dev@lists•linuxfoundation.org>> wrote: >> >> Hello everyone, >> >> We would like to propose a new BIP to extend OP_CSV (and/or OP_CLTV) in >> order for these to allow and interpret negative values. This way, >> taking the example shown in BIP 112: >> >> HASH160 <revokehash> EQUAL >> IF >> <Bob's pubkey> >> ELSE >> "24h" CHECKSEQUENCEVERIFY DROP >> <Alice's pubkey> >> ENDIF >> CHECKSIG >> >> that gives ownership only to Bob for the first 24 hours and then to >> whichever spends first, we basically propose using the negative bit value: >> >> HASH160 <revokehash> EQUAL >> IF >> <Bob's pubkey> >> ELSE >> "-24h" CHECKSEQUENCEVERIFY DROP >> <Alice's pubkey> >> ENDIF >> CHECKSIG >> >> meaning that both would have ownership for the first 24 hours, but >> after that only Bob would own such coins. Its implementation should >> not be too tedious, and in fact it simply implies considering negative >> values that are at the moment discarded as for the specification of >> BIP-112, leaving the sign bit unused. >> >> This, we argue, an increase the fairness of the users, and can at times >> be more cost-effective for users to do rather than trying a Replace-By-Fee >> transaction, should they want to modify such payment. >> >> We would like to have a discussion about this before proposing the >> BIP, for which we are preparing the text. >> >> You can find our paper discussing it here: >> https://hal-cea.archives-ouvertes.fr/cea-01867357 (find attached as well) >> >> Best, >> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 9:19 [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' Alejandro Ranchal Pedrosa 2018-09-06 13:31 ` Matt Corallo @ 2018-09-06 15:16 ` Gregory Maxwell 2018-09-06 20:32 ` Brandon Smith 2018-09-06 16:14 ` vizeet srivastava 2 siblings, 1 reply; 11+ messages in thread From: Gregory Maxwell @ 2018-09-06 15:16 UTC (permalink / raw) To: a.ranchalpedrosa, Bitcoin Dev; +Cc: sara.tucci, Onder.GURCAN Functionality such as this does not currently exist not because no one thought of it before, but because it has been proposed many times before and determined to be harmful. The existing design of CLTV/CSV were carefully constructed to make it impossible for a transaction to go from valid to invalid based on the time. The most naive construction-- e.g. push the current time/height on the stack-- would have that property and was specifically avoided. When a spend goes from valid to invalid it means that a reorganization will destroy coins even completely absent any dishonest actions of the coins prior owner in the coins recent casual history. Effectively a coin with any kind of non-monotone validity event in its recent history functions like a recently generated coin: a coin that reorgs destroy. Bitcoin addresses the issue for recently generated coins by not permitting their use for 100 blocks. I've yet to see an argument for a use case for non-monotone validity that still sounds useful once the negative effects are addressed (e.g. by subjecting coins that have gone through them to a maturity limitation). ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 15:16 ` Gregory Maxwell @ 2018-09-06 20:32 ` Brandon Smith 2018-09-07 5:02 ` Terry McLaughlin 2018-09-07 7:12 ` Alejandro Ranchal Pedrosa 0 siblings, 2 replies; 11+ messages in thread From: Brandon Smith @ 2018-09-06 20:32 UTC (permalink / raw) To: Gregory Maxwell, Bitcoin Protocol Discussion Cc: sara.tucci, Onder.GURCAN, a.ranchalpedrosa I made a similar proposal about 7 months ago, and documented some of the discussion points here: https://github.com/reardencode/bips/blob/reverselocktime/bip-0zzz.mediawiki On 2018-09-06 (Thu) at 15:16:34 +0000, Gregory Maxwell via bitcoin-dev wrote: > Functionality such as this does not currently exist not because no one > thought of it before, but because it has been proposed many times > before and determined to be harmful. The existing design of CLTV/CSV > were carefully constructed to make it impossible for a transaction to > go from valid to invalid based on the time. The most naive > construction-- e.g. push the current time/height on the stack-- would > have that property and was specifically avoided. > > When a spend goes from valid to invalid it means that a reorganization > will destroy coins even completely absent any dishonest actions of the > coins prior owner in the coins recent casual history. Effectively a > coin with any kind of non-monotone validity event in its recent > history functions like a recently generated coin: a coin that reorgs > destroy. Bitcoin addresses the issue for recently generated coins by > not permitting their use for 100 blocks. I've yet to see an argument > for a use case for non-monotone validity that still sounds useful once > the negative effects are addressed (e.g. by subjecting coins that have > gone through them to a maturity limitation). > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 20:32 ` Brandon Smith @ 2018-09-07 5:02 ` Terry McLaughlin 2018-09-07 7:12 ` Alejandro Ranchal Pedrosa 1 sibling, 0 replies; 11+ messages in thread From: Terry McLaughlin @ 2018-09-07 5:02 UTC (permalink / raw) To: Brandon Smith, Bitcoin Protocol Discussion [-- Attachment #1: Type: text/plain, Size: 2004 bytes --] Please help me guide me in the direction I need to go On Thursday, September 6, 2018, Brandon Smith via bitcoin-dev < bitcoin-dev@lists•linuxfoundation.org> wrote: > I made a similar proposal about 7 months ago, and documented some of the > discussion points here: > > https://github.com/reardencode/bips/blob/reverselocktime/bip-0zzz. > mediawiki > > On 2018-09-06 (Thu) at 15:16:34 +0000, Gregory Maxwell via bitcoin-dev > wrote: > > Functionality such as this does not currently exist not because no one > > thought of it before, but because it has been proposed many times > > before and determined to be harmful. The existing design of CLTV/CSV > > were carefully constructed to make it impossible for a transaction to > > go from valid to invalid based on the time. The most naive > > construction-- e.g. push the current time/height on the stack-- would > > have that property and was specifically avoided. > > > > When a spend goes from valid to invalid it means that a reorganization > > will destroy coins even completely absent any dishonest actions of the > > coins prior owner in the coins recent casual history. Effectively a > > coin with any kind of non-monotone validity event in its recent > > history functions like a recently generated coin: a coin that reorgs > > destroy. Bitcoin addresses the issue for recently generated coins by > > not permitting their use for 100 blocks. I've yet to see an argument > > for a use case for non-monotone validity that still sounds useful once > > the negative effects are addressed (e.g. by subjecting coins that have > > gone through them to a maturity limitation). > > _______________________________________________ > > bitcoin-dev mailing list > > bitcoin-dev@lists•linuxfoundation.org > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > [-- Attachment #2: Type: text/html, Size: 2814 bytes --] ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 20:32 ` Brandon Smith 2018-09-07 5:02 ` Terry McLaughlin @ 2018-09-07 7:12 ` Alejandro Ranchal Pedrosa 2018-09-07 12:51 ` Brandon Smith 1 sibling, 1 reply; 11+ messages in thread From: Alejandro Ranchal Pedrosa @ 2018-09-07 7:12 UTC (permalink / raw) To: Brandon Smith, Gregory Maxwell, Bitcoin Protocol Discussion; +Cc: Onder.GURCAN [-- Attachment #1: Type: text/plain, Size: 1054 bytes --] Hi all, Thank you for the link, and also to Gregory for the remarks. I did not know about this previous proposal. I think the last paragraph of future work is interesting: "It may be interesting to add enhance OP_CHECKSEQUENCEVERIFY <https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki> to allow outputs that are spendable by Alice until time foo, always spendable by Bob, and spendable by Joe only after time bar, or other such cases" Perhaps it would allow this functionality, while keeping the validity of coins, if the new OP_zzz took an additional argument than suggested, such that the first one is the timelimit for Alice to keep the coin (say in the first 24 hours), and after those 24 hours the ownership goes to the third argument, say Bob. That is, it is not possible to use only specifying the owner in the first 24 hours. Would this be considered harmful? Best, Alejandro. On 9/6/18 10:32 PM, Brandon Smith wrote: > ade a similar proposal about 7 months ago, and documented some of the > discussion points here: [-- Attachment #2: Type: text/html, Size: 1584 bytes --] ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-07 7:12 ` Alejandro Ranchal Pedrosa @ 2018-09-07 12:51 ` Brandon Smith 2018-09-07 13:47 ` TUCCI Sara 0 siblings, 1 reply; 11+ messages in thread From: Brandon Smith @ 2018-09-07 12:51 UTC (permalink / raw) To: Alejandro Ranchal Pedrosa; +Cc: Bitcoin Protocol Discussion, Onder.GURCAN I believe you may be missing the overall points in the "Nail In the Coffin" and "Temporary Discussion" sections. In summary: 1: Any UTXO spending a script with an expiration must be treated similarly to Coinbase (I proposed a solution to this, but it's complex and may have unforeseen implications). 2: All existing software assumes that a transaction once valid stays valid. Any proposal to change this must ensure that existing wallets and users aren't immediately open to being scammed by malicious actors sending low fee expiring transactions. The more tenable ways to move forward on improving the ecosystem around delayed transactions and refunds are: Lightning, improved fee estimation, and improved mempool eviction / re-propagation resistance. The original reason that I began looking into this is because I noticed that during high fee periods, transactions could re-propagate between mempools of differing policies resulting in coins being stuck unusable for far longer than the expected 1-2 week eviction. I don't know of any concrete work going into investigating or improving this. HTH, --Brandon On 2018-09-07 (Fri) at 09:12:40 +0200, Alejandro Ranchal Pedrosa wrote: > Hi all, > > Thank you for the link, and also to Gregory for the remarks. I did not > know about this previous proposal. I think the last paragraph of future > work is interesting: > > "It may be interesting to add enhance OP_CHECKSEQUENCEVERIFY > <https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki> to > allow outputs that are spendable by Alice until time foo, always > spendable by Bob, and spendable by Joe only after time bar, or other > such cases" > > Perhaps it would allow this functionality, while keeping the validity of > coins, if the new OP_zzz took an additional argument than suggested, > such that the first one is the timelimit for Alice to keep the coin (say > in the first 24 hours), and after those 24 hours the ownership goes to > the third argument, say Bob. > > That is, it is not possible to use only specifying the owner in the > first 24 hours. Would this be considered harmful? > > Best, > > Alejandro. > > On 9/6/18 10:32 PM, Brandon Smith wrote: > > ade a similar proposal about 7 months ago, and documented some of the > > discussion points here: ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-07 12:51 ` Brandon Smith @ 2018-09-07 13:47 ` TUCCI Sara 0 siblings, 0 replies; 11+ messages in thread From: TUCCI Sara @ 2018-09-07 13:47 UTC (permalink / raw) To: Brandon Smith, Alejandro Ranchal Pedrosa Cc: Bitcoin Protocol Discussion, GÜRCAN Onder Hello Gregory, all Thank you so much for your feedback. Our main objective in the research paper was in fact to study the "what-if" situation in which Bitcoin offered the cancellation of the transaction from the user's point of view. Our main interest was the model of the user-agents and quantify the possible "satisfaction" that the user can obtain while also quantifying a possible greater satisfaction with the respect to the current situation. When we wrote the document, we thought about the "implementability" of the cancellation through non-monotonous validity to obtain a more realistic model, but being very cautious in proposing or claiming any kind of mechanism. Of course we never thought that nobody ever proposed it before, that's why when we finished writing the paper, many questions remained unanswered and we decided to send you the document, to get your opinion, which is very useful for improving the current model. Although Bitcoin will never implement the mechanism because arguments for non-monotonous validity use case will not emerge, I think this type of study can be useful to conclude on that opportunity or as Brandon suggested to move to other approaches, like Lightning (even though even for Lightning several limitations still there exist !). Sara P.S. Sorry for possible multiple copies of the message, I needed to subscribe to the mailing list and to repost __ On 07/09/2018, 14:51, "Brandon Smith" <freedom@reardencode•com> wrote: I believe you may be missing the overall points in the "Nail In the Coffin" and "Temporary Discussion" sections. In summary: 1: Any UTXO spending a script with an expiration must be treated similarly to Coinbase (I proposed a solution to this, but it's complex and may have unforeseen implications). 2: All existing software assumes that a transaction once valid stays valid. Any proposal to change this must ensure that existing wallets and users aren't immediately open to being scammed by malicious actors sending low fee expiring transactions. The more tenable ways to move forward on improving the ecosystem around delayed transactions and refunds are: Lightning, improved fee estimation, and improved mempool eviction / re-propagation resistance. The original reason that I began looking into this is because I noticed that during high fee periods, transactions could re-propagate between mempools of differing policies resulting in coins being stuck unusable for far longer than the expected 1-2 week eviction. I don't know of any concrete work going into investigating or improving this. HTH, --Brandon On 2018-09-07 (Fri) at 09:12:40 +0200, Alejandro Ranchal Pedrosa wrote: > Hi all, > > Thank you for the link, and also to Gregory for the remarks. I did not > know about this previous proposal. I think the last paragraph of future > work is interesting: > > "It may be interesting to add enhance OP_CHECKSEQUENCEVERIFY > <https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki> to > allow outputs that are spendable by Alice until time foo, always > spendable by Bob, and spendable by Joe only after time bar, or other > such cases" > > Perhaps it would allow this functionality, while keeping the validity of > coins, if the new OP_zzz took an additional argument than suggested, > such that the first one is the timelimit for Alice to keep the coin (say > in the first 24 hours), and after those 24 hours the ownership goes to > the third argument, say Bob. > > That is, it is not possible to use only specifying the owner in the > first 24 hours. Would this be considered harmful? > > Best, > > Alejandro. > > On 9/6/18 10:32 PM, Brandon Smith wrote: > > ade a similar proposal about 7 months ago, and documented some of the > > discussion points here: ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' 2018-09-06 9:19 [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' Alejandro Ranchal Pedrosa 2018-09-06 13:31 ` Matt Corallo 2018-09-06 15:16 ` Gregory Maxwell @ 2018-09-06 16:14 ` vizeet srivastava 2 siblings, 0 replies; 11+ messages in thread From: vizeet srivastava @ 2018-09-06 16:14 UTC (permalink / raw) To: Alejandro Ranchal Pedrosa, Bitcoin Protocol Discussion Cc: TUCCI Sara, Önder GÜRCAN [-- Attachment #1: Type: text/plain, Size: 2092 bytes --] I feel it is breaking a principle that if a transaction is valid it remains valid. There might be dangerous repercussions to breaking that rule. For instance chain of transaction become invalid which might lead to losses. On Thu 6 Sep, 2018, 6:37 PM Alejandro Ranchal Pedrosa via bitcoin-dev, < bitcoin-dev@lists•linuxfoundation.org> wrote: > Hello everyone, > > We would like to propose a new BIP to extend OP_CSV (and/or OP_CLTV) in > order for these to allow and interpret negative values. This way, > taking the example shown in BIP 112: > > HASH160 <revokehash> EQUAL > IF > <Bob's pubkey> > ELSE > "24h" CHECKSEQUENCEVERIFY DROP > <Alice's pubkey> > ENDIF > CHECKSIG > > that gives ownership only to Bob for the first 24 hours and then to > whichever spends first, we basically propose using the negative bit value: > > HASH160 <revokehash> EQUAL > IF > <Bob's pubkey> > ELSE > "-24h" CHECKSEQUENCEVERIFY DROP > <Alice's pubkey> > ENDIF > CHECKSIG > > meaning that both would have ownership for the first 24 hours, but > after that only Bob would own such coins. Its implementation should > not be too tedious, and in fact it simply implies considering negative > values that are at the moment discarded as for the specification of > BIP-112, leaving the sign bit unused. > > This, we argue, an increase the fairness of the users, and can at times > be more cost-effective for users to do rather than trying a Replace-By-Fee > transaction, should they want to modify such payment. > > We would like to have a discussion about this before proposing the > BIP, for which we are preparing the text. > > You can find our paper discussing it here: > https://hal-cea.archives-ouvertes.fr/cea-01867357 (find attached as well) > > Best, > > -- > Alejandro Ranchal Pedrosa, Önder Gürcan and Sara Tucci-Piergiovanni > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > [-- Attachment #2: Type: text/html, Size: 2874 bytes --] ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2018-09-07 13:47 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-06 9:19 [bitcoin-dev] A BIP proposal for transactions that are 'cancellable' Alejandro Ranchal Pedrosa
2018-09-06 13:31 ` Matt Corallo
[not found] ` <CABaiX-2L9oVdta=aRH91uE=iPRv4cX6zU0=+oF+2oWqnu=64YQ@mail.gmail.com>
2018-09-06 16:33 ` Matt Corallo
2018-09-07 7:07 ` Alejandro Ranchal Pedrosa
2018-09-06 15:16 ` Gregory Maxwell
2018-09-06 20:32 ` Brandon Smith
2018-09-07 5:02 ` Terry McLaughlin
2018-09-07 7:12 ` Alejandro Ranchal Pedrosa
2018-09-07 12:51 ` Brandon Smith
2018-09-07 13:47 ` TUCCI Sara
2018-09-06 16:14 ` vizeet srivastava
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox