By Bitcoin Revista - Hace 6 meses - Tiempo de lectura: 15 minutos
Control de monedas de dos caras
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Self custody is an essential requirement when using Bitcoin to fully benefit from all the properties that make Bitcoin valuable in the first place. To be able to truly transact without permission, benefiting from the censorship resistance of the network, you have to control your own keys. You can’t outsource that to someone else, you can’t trust the neutrality or honesty of a custodian, you must solely have direct control of corresponding private keys to your UTXOs. If you fail to do this, you will always be a second class user. Bitcoin as a system gives you almost total control over your own funds; control of custody, when it is spent and how it is spent, even the ability to completely destroy your coins through deleting your private keys.
When you outsource that direct control of the actual Bitcoin UTXOs on the network to a third party, you relinquish that control in its entirety. That’s not to say that there aren’t middle grounds to that, such as Lightning, Statechains, and other proposed second layer designs, but ignoring those for a moment, when you do not control your UTXOs directly, you do not have the ability to transact whenever and however you want. You do not have the ability to destroy and render your coins inaccessible if you want. You do not have something that is permissionless in your ownership and control.
So why do people choose not to withdraw their coins and leave them with a custodian? Some combination of apathy, lack of understanding, fear or doubt about their ability to correctly manage their own keys without losing money, or even concerns over being able to physically keep their keys safe. There are numerous reasons, and over time we will have different solutions to address the root cause. But one of the big causes for such a choice has yet to even really happen to any serious degree; the raw economics of blockspace utilization. If you only have a couple of dollars of bitcoin –or even less in the case of zapping satoshis around with things like custodial Lightning solutions– you cannot practically take control of those coins or spend them on chain cost effectively. Even when fees get that high however, it's still cost effective for a user in such a situation to handle their Bitcoin until they have enough to be able to afford to withdraw to self-custody at a reasonable cost.
That is not going to be the case forever. No matter what happens, if Bitcoin actually succeeds and becomes widely adopted for real use among normal people, that cost of blockspace is going to trend up; a tide that continues rising in sync with the growth of users forever. It will even rise without user growth whenever economic activity and money velocity picks up among the existing userbase. It is an inevitable reality, it cannot be stopped by anything short of the stagnation or complete failure of Bitcoin misma.
So what is the solution here? That is pretty much the root of the tug of war between the old big block versus small block divide that has been going on since the beginning of Bitcoin. Taking custody of your own bitcoin by having them sent to key pairs you control is a foundational aspect to Bitcoin, but so is being able to actually validate that a Bitcoin UTXO controlled by a key you possess was really created on-chain. The relationship between the costs of these two things is, and will forever be, an eternal tug of war between the costs of one versus the other. If you make the verification cost of blockspace cheaper and increase its availability, more people will utilize it. If you make the use of it more efficient, more people will utilize it.
You can tweak those variables all day long, back and forth, you can make computational verification cheaper, you can make blockspace use more efficient, but either one will just enable more people to use it and inevitably (unless we are all wrong about Bitcoin) lead to an increase in demand for blockspace. And that is just looking at things in a basic vacuum of economics and how demand and availability regulate each other. That isn’t even considering the actual engineering trade-offs of the specific ways to accomplish either thing, and the downside risks each optimization creates.
Y hay muchas compensaciones involucradas en todas las formas específicas en que se puede lograr cualquiera de esos objetivos. Mucho. Incluso el protocolo Lightning, con toda la brillantez de la ingeniería detrás de él, que proporciona un aumento exponencial en el rendimiento transaccional, tiene enormes ventajas y desventajas. Es el protocolo de segunda capa más escalable y, al mismo tiempo, menos confiable propuesto hasta ahora en términos de rendimiento versus falta de confianza. Pero incluso esto tiene desventajas y diferencias fundamentales.
Haga clic en la imagen de arriba para suscribirse.El modelo de seguridad de Lightning es reactivo, lo que significa que la única forma de asegurarse de no perder dinero es prestar atención a las blockchain y reaccionar lo suficientemente rápido si alguien intenta robarle fondos enviando un estado de canal antiguo a la cadena. Si bien esta es una solución perfectamente viable para ese problema, es una gran desviación del modelo de seguridad de simplemente tener un UTXO unilateralmente. Todo lo que tiene que hacer en esa situación es verificar una vez que una moneda que se le envió en cadena fue realmente confirmada y listo. No es necesario que prestes atención continuamente a nada después de eso para mantener tu dinero seguro.
This fundamental difference between using bitcoin through Lightning rather than directly on chain will have a lot of consequences for users with less money or cost tolerance for blockspace. The higher the average fee rate trends up, the more people will be pushed into locking their coins on Lightning to be able to actually spend them more cost effectively. It doesn’t even begin to end there with them being forced into a reactive security model though. Lightning routes payments through Hash Time Lock Contracts to guarantee that the money is fully sent or fully refunded across an entire payment route. This is actually never done for small value payments that are not cost effective to enforce on the blockchain if necessary. Those 1-2 satoshi payments getting zapped around for fun are sent in an entirely trusted fashion without using HTLCs and just hoping no one along the path screws up or refuses to cooperate. As fees rise on the base layer, this will have to be done for larger and larger payments. It makes zero economic sense to spend $5 in fees to enforce a payment worth only $1. Imagine $10 fees, $20 fees, etc. As the fee market matures and the base level of fees rise, even the nature of payments across the Lightning Network will fundamentally change, moving from a trustless system enforceable on-chain to one ultimately depending on honest behavior.
La misma dinámica afectará a si un usuario puede o no abrir y mantener un canal Lightning en primer lugar (o si alguien más querrá asignar liquidez a ese canal para que el usuario tenga capacidad de recepción). Si va a costar $10 realizar transacciones en la cadena, entonces inmediatamente tendrá que pagar $20 (suponiendo que las tarifas no empeoren) por abrir e inevitablemente cerrar ese canal. Si tiene que cerrar de manera no cooperativa, incluso sin HTLC en curso, son $ 30 porque ese cierre requiere dos transacciones. ¿Cuánto dinero necesitará la gente invertir en un canal para considerar tarifas tan altas que valgan la pena? Las cosas comenzarán a volverse muy excluyentes muy rápidamente cuando las tarifas realmente comiencen a crecer para siempre cuando la demanda de espacio en bloques se sature.
So what does this mean? Lightning isn’t enough. It gives a lot more headroom in scaling self-custody, but it does not completely solve the problem and will itself wind up subjected to the exact same economic scaling issues that are present on the base layer of the blockchain. Not to mention introducing new security assumptions in the process along the way. It’s like building up a barrier of sandbags around your house in a flood; it will keep your house safe as long as the water level doesn’t rise above it. But if we are right about Bitcoin and its adoption continues unabated, the water level will keep rising well above the top of that barrier. Lightning by itself is not enough to raise the barrier much higher.
¿Qué alternativa concreta y desplegada puede elevarlo más alto? Las cadenas estatales son un ejemplo concreto. Pueden lograr un aumento masivo en la eficiencia del uso del espacio de bloques, pero, sorpresa (no debería ser una sorpresa), introducen incluso más compensaciones que Lightning. Cuando trabajas con un canal Lightning, lo abres a una contraparte específica y esa es la única persona con la que puedes interactuar. Para cambiar la persona con la que estás interactuando para acceder a las rutas de otras personas, en realidad tienes que cerrar ese canal en la cadena y abrir uno nuevo con otra persona. Las cadenas estatales cambian por completo la dinámica allí.
Con una statechain, puedes transferir monedas a cualquier persona nueva con la que nunca hayas interactuado antes, completamente fuera de la cadena. Pero solo puede transferir el UTXO completo y está involucrado un tercero como árbitro. Desventaja número uno; Una vez que bloqueas una moneda en una cadena de estado, todo se puede transferir fuera de la cadena, pero solo todo a la vez. En segundo lugar, toda la forma en que funciona es esencialmente confiar en un tercero neutral para que coopere exclusivamente con el propietario actual. La forma real en que se aplica en la cadena se puede hacer de diferentes maneras, pero la más larga y la más corta es que el propietario original crea una cadena de estado bloqueando monedas al estilo Lightning con un operador de servicios y obtiene una transacción de retiro prefirmada que está bloqueado en el tiempo al igual que en Lightning para retirarse unilateralmente. El truco es que al configurar el "multisig", se utiliza un esquema como Schnorr donde solo hay una clave de la que cada parte tiene una parte. Existen protocolos criptográficos que se pueden utilizar para regenerar claves compartidas de manera que los sucesivos usuarios y el operador del servicio terminen con diferentes claves compartidas, lo que equivale a la misma clave pública. Cuando se transfiere una cadena de estado, el remitente, el receptor y el operador participan en un protocolo fuera de la cadena y el operador elimina su parte anterior del propietario anterior, por lo que ni siquiera son capaces de firmar algo en cooperación con ese usuario.
Lightning es esencialmente un acuerdo unilateral entre dos usuarios en el que cualquiera de ellos puede hacer cumplir la cadena en cualquier momento, siempre que presten atención a la cadena de bloques. Pero no se pueden cambiar los participantes del canal en ese acuerdo sin ingresar a la cadena y pagar las tarifas necesarias. Por cómo funciona el mecanismo de seguridad de la sanción (quitarle todo el dinero a alguien que intentó hacer trampa con un antiguo Estado), tampoco se pueden crear esos acuerdos entre más de dos personas. Es (prácticamente, no literalmente, debido al costo computacional) imposible encontrar una manera de asignar culpas y penalizar sólo a la parte correcta en acuerdos entre más de dos personas.
Las cadenas estatales son el mismo tipo de acuerdo, excepto que son indefinidos en cuanto a quién puede participar, siempre y cuando cualquiera que quiera estar dispuesto a confiar en el operador del servicio, que cabe señalar, puede estar federado entre un grupo y puede aplicarse unilateralmente como siempre y cuando observe que la cadena de bloques y los operadores de servicios se comportan honestamente.
Lo que sucedió aquí en esta progresión, desde Lightning hasta Statechain, es que ha hecho posible que más de dos personas interactúen de manera segura fuera de la cadena si están dispuestas a confiar en una parte neutral para imponer un resultado honesto. Por lo tanto, se ganó una gran escalabilidad por el costo de introducir confianza además del requisito ya existente de permanecer en línea y observar la cadena de bloques.
¿Por qué? Porque esa es realmente la única manera de lograr esa mayor escalabilidad sin agregar nuevas funciones a la cadena de bloques. Agregue confianza a la imagen. Tal como están las cosas ahora, probablemente podamos lograr una gran escalabilidad en la cadena de bloques sin recurrir a la custodia total confiando en que una sola entidad no robe su dinero, pero cada paso que demos hacia una mayor escalabilidad introducirá más confianza.
No hay manera de evitarlo; O es necesario agregar una nueva funcionalidad a la cadena de bloques o nosotros, como colectivo de diferentes grupos de usuarios, debemos aceptar que así será. Más confianza se está infiltrando en los límites para casos de uso de menor valor y usuarios de menor patrimonio neto.
There has been quite a lot of concern and discussion around this entire dynamic this year. The higher the average fee trends for space in a block, the more people will be priced out of using Bitcoin, even when you take into account things like the Lightning Network. Inscriptions and Ordinals caused a massive divide in the more active minority of people in this space, and all of it at the root was centered around the dynamic of one use case potentially raising the fees for blockspace to the point that another use case was priced out of being viable on Bitcoin.
It has been a very illuminating year so far watching people call Taproot a mistake, rally around publicly decrying the incompetence of developers in not realizing what they did, and dig in further into a dogmatic attitude. “Never upgrade or change Bitcoin again because it is perfect and infallible.” These same people in a vast overlap tend to also be the same people championing Bitcoin as a tool for self-sovereignty. They seem to always be the same people preaching self custody as a magic remedy for everything, and when scaling problems get brought up? Oh, Lightning is THE solution to that. Then they point at Ordinals and inscriptions again and start screaming about how one use case will price out another one, and so that bad one has to be stopped.
It is missing the forest for the trees. Any use of bitcoin that is profitable and cost effective to deal with demand is going to happen. There is literally no way to stop that, and Bitcoiners convincing themselves they can are fooling themselves. All of the backlash against Ordinals and Inscriptions very quickly led to people intentionally doing even more costly things like STAMPS, which instead of using witness data that doesn’t have to be stored in the UTXO set, puts their data inside the actual UTXOs. Rather than acknowledging the reality that if people think it is profitable to pay for blockspace they will, many people are falling victim to a knee jerk reaction of trying to stop what they think is bad while completely ignoring the reality that there are other worse ways to accomplish the same thing anyway if it makes economic sense. An impulsive reaction to the rise of Ordinals and Inscriptions is dragging down the entire attention span of involved people in this space into a pit of wasted efforts to stop things causing fee pressure that they don’t agree with instead of considering how to adapt and scale things they do agree with to that fee pressure.
Haga clic en la imagen de arriba para descargar el (PDF).Un buen porcentaje de las personas que participan de esta manera están literalmente discutiendo con el viento. Están tratando de decirnos que dejemos de soplar porque es derribar cosas en lugar de atarlas o cargar los cimientos para resistirlos. Si bloquea o censura inscripciones con éxito, la gente simplemente usará STAMPS, OP_RETURN o técnicas que desperdician aún más recursos de red.
Ultimately no technical filter will be good enough to stop people from doing dumb or non-monetary things with the Bitcoin network. The only filter that will successfully stop anything from being done on Bitcoin is economics. And that filter is equally created and equally affects every use of Bitcoin. It’s time to stop trying to fight externalities driven by economic demand and try to counter them through improving efficiency.
Si usted piensa Bitcoin’s primary value and purpose is to transfer value, then rather than obsess over somehow stopping all other uses of Bitcoin, you should be focused on considering the trade offs of different mechanisms that can improve its efficiency in transferring value. You are either going to have to choose between progressively adding more trust to things in order to accomplish that, or adding new features to the Bitcoin protocol itself to build more efficient things without depending on trust.
Buraq, el infame asesino de Lightning, propuso recientemente TBDxxx, un nuevo protocolo de segunda capa. Es esencialmente un gran sistema statechain/ecash multipartidista que no tiene custodia, no requiere confiar en el operador del servicio como una statechain y puede agrupar a muchos usuarios en un único UTXO en cadena. Esto requiere ANYPREVOUT(APO) o CHECKTEMPLATEVERIFY(CTV) para funcionar, por lo que necesita un cambio por consenso. Las fábricas de canales son una forma de tomar un único UTXO y apilar canales Lightning uno encima del otro, de modo que un UTXO puede representar a docenas de usuarios que tienen un canal Lightning normal en la parte superior. Esto también requiere ANYPREVOUT.
Both of these proposals can scale the use of Bitcoin to transfer value much further than Lightning can now, but ultimately both of them are subject to the same economic fee pressure that Lightning and on-chain use are. To join one of these multiparty channel pools, or exit one, or enforce something non-cooperatively on chain you still have to pay fees. For something like a channel factory this will involve one person who needs to close or enforce something actually unfurling and closing (fully or partially) the entire channel factory with everyone in it, creating costs and on-chain implications for everyone. Even despite accomplishing a huge increase in scalability without trust, it still falls victim to the effects of the blockspace market maturing.
Para mitigar (no resolver) esto, probablemente necesitaremos aún más códigos OP. Cosas como OP_EVICT o TAPLEAFUPDATEVERIFY. OP_EVICT permite que un grupo expulse colectivamente a un miembro no cooperativo de un canal multipartito sin cerrar ni afectar a nadie más en él mediante una única transacción con una entrada y dos salidas. Esto no resuelve el problema, pero lo hace mucho más eficiente al permitir que una persona sea desalojada con una huella en la cadena mucho menor. TLUV logra lo mismo excepto que en lugar de que todos los demás echen a alguien, permite que un solo usuario retire todos sus fondos sin molestar a nadie ni necesitar que nadie más coopere.
To address more of the issues, we need to make more changes to Bitcoin. There’s no way around that. Taproot “opened the door” to Inscriptions in the sense that it relaxed limits enough for people to go nuts with it, but they were already possible before Taproot. You can look at Taproot as having provided efficiency gains for both monetary use cases as well as non-monetary use cases. It made multisig the same size as a regular single sig address, which helps make using a higher security set up for keys or second layer protocols cheaper, but it also made it cheaper to inscribe arbitrary data.
Two sides of the same coin. And that is how it is. Same as it ever was. Making use of the blockchain more efficient is not always going to improve solely the use case you want, but it is absolutely necessary to scale Bitcoin in a way that is self-sovereign and self-custodial. It’s time to either accept that and start considering the reality of finding the optimal efficiency gains for value transfer with the least efficiency gains for detrimental or non-value transfer uses, or it’s time to accept that the only way to scale value transfer is to introduce trust.
A good number of people in this space have already made their choice one way or another, but there is a large contingent of people in the middle who refuse to accept either. This loud group in the middle needs to wake up and smell the coffee, and accept the reality of the situation. This is how blockchains work. Pick one; either brace yourself to accept the injection of trust into things, or accept the reality that changes need to happen. You can tell yourself all day long that you don’t have to choose, but your actions in attacking the notion of any change to Bitcoin at all while simultaneously championing self-custodial Bitcoin as a solution for the world are implicitly making the choice to accept more trust being introduced into the system, whether you want to acknowledge that or not.
Este artículo aparece en Bitcoin Revista “La cuestión de la retirada”. Haga click aquí para suscribirse.
Un folleto en PDF de este artículo está disponible para descargar.
Fuente original: Bitcoin Revista