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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Good evening ZmnSCPxj, That you for your considered discussion. Am I wrong to think that any fullnode can validate blocks conform to a prob= ability distribution? In my understanding after adoption of the proposal, a= ny full node could validate all properties that a block has that they now v= alidate, apart from block size, and additionally that the block conforms to= a probability distribution. It seems a yes-no result. Let us assume that s= uch a probability distribution exists since the input is a probability. Before or after the proposal, miners could falsify transactions if there is= a feasible way for them to do this. The introduction of the proposal does = not change that fact. At the moment the incentive to falsify transactions i= s to fill blocks so that real transactions must pay the highest possible fe= es in the auction for limited transaction bandwidth resulting in a net gain= for miners. Simply making bigger blocks serves no economic purpose in itse= lf, since the miners we presume must pay the fees for their falsified trans= actions, there is no net gain, the fee will be distributed through the pool= . Unless, by miners, I may presume we mostly mean mining pools and collusio= n. Still, where is the gain? It is only the blocks that will be larger with= no economic advantage. In a fee for priority service auction, there is always limited space in eac= h new block since it represents only a small fraction of the size of the me= mpool. Presenting fraudulent transactions at the bottom end of the scale ha= s limited effect on the cost of being near the front of the queue, at prior= ity. As the fraudulent transactions age they would be included in blocks pr= esuming the fee is above dust level, but the block size would grow to accom= modate them since the valid mempool is larger. The auction for priority sti= ll continues uninterrupted at the top of the priority curve. There is nothi= ng stopping a motivated individual now from writing a script to create a mi= llion pointless dust transactions per day, flooding the mempool. Even if th= e fee is above dust level the proposal does not change this but, ensures tr= ansactional reliability for valid transactions. In an idealist world, all nodes could agree on the state of the mempool. I = agree, there is no feasible way currently to hold the mempool to consensus = without a network of dedicated mempool servers. As it is, it has been sugge= sted that all long-running nodes will have approximately a similar view of = the mempool. Sweeping the entire mempool contents per block would achieve w= hat is required if there was a mempool consensus but since it will just be = one node's view of the mempool that will not be the result. My speculation is that as a result of the proposal, through increased adopt= ion of Bitcoin over time there would, in fact, be more transactions and gre= ater net fees paid per day. An increased value of BTC that we suppose would= follow from increased usage would augment this fee value increase. It sure= ly follows that a more stable and reliable service will have greater consum= er and business acceptance, and there it follows that this is in miners fin= ancial interest. I have not considered a maxblocksize since I consider that the mempool can = eventually grow infinitely in size just in valid transactions, without even= any fraudulent transactions. I suppose that in time it will become necessa= ry to start all new nodes in pruned mode by default due to the onerous stor= age requirements of the full blockchain. I do not think that the proposed c= hanges alter this. I am sure that there is much more to write. Regards, Damian Williamson ________________________________ From: ZmnSCPxj Sent: Wednesday, 27 December 2017 2:55 PM To: Damian Williamson Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] BIP Proposal: Revised: UTPFOTIB - Use Transactio= n Priority For Ordering Transactions In Blocks Good morning Damian, I see you have modified your proposal to be purely driven by miners, with f= ullnodes not actually being able to create a strict "yes-or-no" answer as t= o block validity under your rules. This implies that your rules cannot be = enforced and that rational miners will ignore your proposal unless it bring= s in more money for them. The fact that your proposal provides some mechan= ism to increase block size means that miners will be incentivized to falsif= y data (by making up their own transactions just above your fixed "dust siz= e" threshhold whatever that threshhold may be -- and remember, miners get a= t least 12.5 BTC per block, so they can make a lot of little falsified tran= sactions to justify every block size increase) until the block size increas= e per block is the maximum possible block size increase. -- Let me then explain proof-of-work and the arrow of time in Physics. It may= seem a digression, but please, bear with me. Proof-of-work proves that work was performed, and (crucially) that this wor= k was done in the past. This is important because of the arrow of time. In principle, every physical interaction is reversible. Visualize a video = of two indivisible particles. The two particles move towards each other, c= ollide, and because of the collision, fly apart. If you ran this video in r= everse, or in forward, it would not be distinguishable to you, as an outsid= e observer, whether the video was running in reverse or not. It seems at s= ome level, time does not exist. And yet time exists. Consider another video, that of a vase being dropped on a hard surface. Th= e vase hits the surface and shatters. Played in reverse, we can judge it a= s nonsensical: scattered pieces of ceramic spontaneously forming a vase and= then flying upwards. This orients our arrow of time: the arrow of time po= ints from states of the universe where lesser entropy exists (the vase is w= hole) to where greater entropy exists (the vase is in many pieces). Indeed, all measures of time are, directly or indirectly, measures of incre= ases in entropy. Consider a simple hourglass: you place it into a state of= low entropy and high energy with most of the sand is in the upper part of = the hourglass. As sand falls, and more of that energy is lost into entropy= , you judge that time passes. Consider a proof-of-work algorithm: you place electrons into a state of low= entropy and high energy. As electrons go through the mining hardware, pro= ducing hashes that pass the difficulty requirement, the energy in those ele= ctrons is lost into entropy (heat), and from the hashes produced (which pro= ves not only that work was done, but in particular, that entropy increased = due to work being done), you judge that time passes. -- Thus, the blockchain itself is already a service that provides a measure of= time. When a block commits to a transaction, then that transaction is kno= wn to have existed at that block height, at the latest. Thus one idea, is to have each block commit to some view of the mempool. I= f a transaction exists in this mempool-view, then you know that the transac= tion is at least that old, and can judge the age from this and use this to = compute the "transaction priority". Unfortunately, transferring the data to prove that the mempool-view is vali= d, is equivalent to always sweeping the entire mempool contents per block. = In that case you might as well not have a block size limit. In addition, miners may still commit to a falsely-empty mempool and deny th= at your transaction is old and therefore priority and therefore will simply= fill their blocks with transactions that have high feerates rather than hi= gh priority. Thus feerate will still be the ultimate measure. Rather than attempt this, perhaps developers should be encouraged to make u= se of existing mechanisms, RBF and CPFP, to allow transactions to be sped u= p by directly manipulating feerates, as priority (by your measure) is not p= ractically computable. Regards, ZmnSCPxj --_000_PS2P216MB0179B1A36650D63AA04566029D070PS2P216MB0179KORP_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Good evening ZmnSCPxj,


That you for your considered disc= ussion.


Am I wrong to think that any fullnode can validate blocks conform to a= probability distribution? In my understanding after adoption of the propos= al, any full node could validate all properties that a block has that they = now validate, apart from block size, and additionally that the block conforms to a probability distribution. It= seems a yes-no result. Let us assume that such a probability distribution = exists since the input is a probability.

Before or after the proposal, miners could falsify transactions if there is= a feasible way for them to do this. The introduction of the proposal does = not change that fact. At the moment the incentive to falsify transactions i= s to fill blocks so that real transactions must pay the highest possible fees in the auction for limited transaction = bandwidth resulting in a net gain for miners. Simply making bigger blocks s= erves no economic purpose in itself, since the miners we presume must pay t= he fees for their falsified transactions, there is no net gain, the fee will be distributed through the pool. Unless= , by miners, I may presume we mostly mean mining pools and collusion. Still= , where is the gain? It is only the blocks that will be larger with no econ= omic advantage.

In a fee for priority service auction, there is always limited space in eac= h new block since it represents only a small fraction of the size of the me= mpool. Presenting fraudulent transactions at the bottom end of the scale ha= s limited effect on the cost of being near the front of the queue, at priority. As the fraudulent transact= ions age they would be included in blocks presuming the fee is above dust l= evel, but the block size would grow to accommodate them since the valid mem= pool is larger. The auction for priority still continues uninterrupted at the top of the priority curve. T= here is nothing stopping a motivated individual now from writing a script t= o create a million pointless dust transactions per day, flooding the mempoo= l. Even if the fee is above dust level the proposal does not change this but, ensures transactional reliabi= lity for valid transactions.

In an idealist world, all nodes could agree on the state of the mempool. I = agree, there is no feasible way currently to hold the mempool to consensus = without a network of dedicated mempool servers. As it is, it has been sugge= sted that all long-running nodes will have approximately a similar view of the mempool. Sweeping the entire= mempool contents per block would achieve what is required if there was a m= empool consensus but since it will just be one node's view of the mempool t= hat will not be the result.

My speculation is that as a result of the proposal, through increased adopt= ion of Bitcoin over time there would, in fact, be more transactions and gre= ater net fees paid per day. An increased value of BTC that we suppose would= follow from increased usage would augment this fee value increase. It surely follows that a more stable and = reliable service will have greater consumer and business acceptance, and th= ere it follows that this is in miners financial interest.

I have not considered a maxblocksize since I consider that the mempool can = eventually grow infinitely in size just in valid transactions, without even= any fraudulent transactions. I suppose that in time it will become necessa= ry to start all new nodes in pruned mode by default due to the onerous storage requirements of the full blockc= hain. I do not think that the proposed changes alter this.

I am sure that there is much more to write.

Regards,
Damian Williamson



From: ZmnSCPxj <ZmnSCP= xj@protonmail.com>
Sent: Wednesday, 27 December 2017 2:55 PM
To: Damian Williamson
Cc: bitcoin-dev@lists.linuxfoundation.org
Subject: Re: [bitcoin-dev] BIP Proposal: Revised: UTPFOTIB - Use Tra= nsaction Priority For Ordering Transactions In Blocks
 
Good morning Damian,

I see you have modified your proposal to be purely driven by miners, w= ith fullnodes not actually being able to create a strict "yes-or-no&qu= ot; answer as to block validity under your rules.  This implies that y= our rules cannot be enforced and that rational miners will ignore your proposal unless it brings in more money for them.&= nbsp; The fact that your proposal provides some mechanism to increase block= size means that miners will be incentivized to falsify data (by making up = their own transactions just above your fixed "dust size" threshhold whatever that threshhold may be -- = and remember, miners get at least 12.5 BTC per block, so they can make a lo= t of little falsified transactions to justify every block size increase) un= til the block size increase per block is the maximum possible block size increase.



--

Let me then explain proof-of-work and the arrow of time in Physics.&nb= sp; It may seem a digression, but please, bear with me.

Proof-of-work proves that work was performed, and (crucially) that thi= s work was done in the past.

This is important because of the arrow of time.

In principle, every physical interaction is reversible.  Visualiz= e a video of two indivisible particles.  The two particles move toward= s each other, collide, and because of the collision, fly apart. If you ran = this video in reverse, or in forward, it would not be distinguishable to you, as an outside observer, whether the video w= as running in reverse or not.  It seems at some level, time does not e= xist.

And yet time exists.

Consider another video, that of a vase being dropped on a hard surface= .  The vase hits the surface and shatters.  Played in reverse, we= can judge it as nonsensical: scattered pieces of ceramic spontaneously for= ming a vase and then flying upwards.  This orients our arrow of time: the arrow of time points from states of the uni= verse where lesser entropy exists (the vase is whole) to where greater entr= opy exists (the vase is in many pieces).

Indeed, all measures of time are, directly or indirectly, measures of = increases in entropy.  Consider a simple hourglass: you place it into = a state of low entropy and high energy with most of the sand is in the uppe= r part of the hourglass.  As sand falls, and more of that energy is lost into entropy, you judge that time passes.<= br>

Consider a proof-of-work algorithm: you place electrons into a state o= f low entropy and high energy.  As electrons go through the mining har= dware, producing hashes that pass the difficulty requirement, the energy in= those electrons is lost into entropy (heat), and from the hashes produced (which proves not only that work was = done, but in particular, that entropy increased due to work being done), yo= u judge that time passes.

--

Thus, the blockchain itself is already a service that provides a measu= re of time.  When a block commits to a transaction, then that transact= ion is known to have existed at that block height, at the latest.

Thus one idea, is to have each block commit to some view of the mempoo= l.  If a transaction exists in this mempool-view, then you know that t= he transaction is at least that old, and can judge the age from this and us= e this to compute the "transaction priority".

Unfortunately, transferring the data to prove that the mempool-view is= valid, is equivalent to always sweeping the entire mempool contents per bl= ock.  In that case you might as well not have a block size limit.

In addition, miners may still commit to a falsely-empty mempool and de= ny that your transaction is old and therefore priority and therefore will s= imply fill their blocks with transactions that have high feerates rather th= an high priority.  Thus feerate will still be the ultimate measure.

Rather than attempt this, perhaps developers should be encouraged to m= ake use of existing mechanisms, RBF and CPFP, to allow transactions to be s= ped up by directly manipulating feerates, as priority (by your measure) is = not practically computable.

Regards,
ZmnSCPxj
--_000_PS2P216MB0179B1A36650D63AA04566029D070PS2P216MB0179KORP_--