Hilo oficial Maidsafe

digipl dijo:

Por supuesto que el problema es una red abierta. Hay mas de 20 años de trabajos sobre los problemas que generan la computación distribuida y centenares de Whitepapers y estudios sobre este tema. De hecho cualquiera que diseñe una solución en un entorno distribuido es lo primero que se debe plantear.

Como tu mismo reconoces si el numero de generales es fijo es posible resolver el problema sin POW. Y ese es el camino que ha seguido Irvine desde el comienzo y lo ha hecho aplicando unos simples principios.

1.-Cambia el "derecho de admisión" global por un "derecho de admisión" local donde el nodo no elije en que grupo se coloca.

2.-Obliga a cualquier integrante de un grupo a trabajar para la red dando espacio y proceso. Si no lo hace se le expulsa. Esto implica que cualquier ataque global a la red, en base a la creación de una mayoría de nodos deshonestos, requiera de grandes recursos.

3.-Todos los integrantes del grupo se conocen ya que, cuando un nodo entra en un grupo ,intercambia sus claves por lo que no es posible que un nodo realice un ataque Sybil dentro de un grupo.

4.-El consenso se realiza, dentro de cada grupo, por mensajes cifrados por lo que, solo es necesario que haya un numero mayor de nodos honestos que deshonestos para solucionar el problema de los generales bizantinos.

Estos pequeños principios son las caricias mentales que nos hacemos. Si encuentras un fallo básico que permita un ataque fácil a la red te agradecería que nos lo dijeras para olvidarnos del asunto. Sino, el que se hace caricias mentales asumiendo cosas que no puede demostrar eres tu.

Y ni Satoshi ni Irvine han hecho ciencia. Ambos se han comportado como ingenieros juntando trabajos de otros para buscar una solución a problemas concretos. El sistema Pow de Satoshi se basó en trabajos de Juels, Brainard, Back y en Papers como este. Irvine hecho mano de trabajos de gente como Naor, Wieder, Woll y trabajos como este.
Como cualquiera con inteligencia, ambos se apoyaron en gigantes.

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Thanks for the explanation, I’ve been looking for a clear description of Maidsafe consensus for a while and this answers it nicely.

So, two questions that were not answered here:

1. What incentivizes nodes to participate honestly?
2. What is the backup/failsafe procedure in the event of a successful collusion on a safecoin? Particularly, if 28 of 32 nodes collude in order to sign off on an infinite number of double spends, then what stops the hyperinflation from getting out of hand before it can somehow be detected and stopped?

The particular nasty attack vector here is that Evil Malicious Mallory writes a patch which, during every consensus round, (i) broadcasts a message to the other co-participants in the consensus group stating “hey, I am evil. What about you?”, and (ii) if it finds 27 other “evil” participants, colludes to hyperinflate the safecoin or do whatever nasty consensus-breaking mechanism. Mallory then pays $5 for every farmer to download this patch. What is the individual incentive not to download the patch? Alternatively, we could have the evil behavior be refusing to sign off on tras*actions, in which case a mere 13% non-altruists can lead to a halt of the network.

Or are you okay assuming a large proportion of altruism and bribe aversion as a security assumption?

(Note that “bribes” in cryptoeconomics do not have to correspond to literal bribes in the real world; they could be an instance of the government applying regulatory pressure to coerce large farms to act in certain ways, or applying pressure to force software developers to add bugs, etc. Given Maidsafe’s emphasis on privacy and freedom, such possibilities are probably something you should care about).

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Nodes are programmed to carry out very simple predefined and deterministically measurable tasks. Not complex languages or similar, in this way many of the attack vectors are confined to what can happen in that realm. So for instance a node need not act with any ‘feeling’ altruistic or not, it only need behave as expected or be noted de-ranked and removed. The key is a very limited specific and measurable set of rules that must be ***owed. There is no notion of honesty in these nodes only logic. This is like the ant analogy I use a lot, complex systems of decentralised control who ***ow very simple rules can create extremely sophisticated communities, but the rules must be simple and measurable. (ya estamos otra vez con las pilinguis hormigas. Esta falacia es la peor de todas. Una hormiga no es un nodo independiente que sigue unas intrucciones simples para cooperar con la colonia. Esto es mentira. Un nodo central, la reina, ha empleado una ingente cantidad de energía en crear a cada una de estas hormigas que, además, es incapaz de compotarse de otro modo del que indica su ADN. Las hormigas no pueden decidir comportarse de forma deshonesta porque no está escrito en su ADN y tampoco deben realizar una prueba de trabajo para demostrar a sus congéneres que son honestas. Símplemente se reconocen unas a otras porque comparten el ADN) Then these can evolve over time, but truly decentralised will miccionan a very minimal set of rules and extremely core algorithms and data types with a genus that is clear and concise.

In the collusion attack you mention the nodes would

1: Have to understand Mallories request (we will not be implementing code to answer Mallory )
2: Not report her to her close group

“Or are you okay assuming a large proportion of altruism and bribe aversion as a security assumption?”

No! but neither would any system. If Mallory sent emails to all bitcoin miners then yes it is a problem for bitcoin. (Esto es falso. Uno no puede enviar emails a los mineros en Bitcoin porque, durante la publicación de la prueba de trabajo, esto es, el nuevo bloque minado, los nodos de la red no conocen qué nodo lo ha minado. Así que ¿A quién vas a mandar el email? ¿Al nodo que te ha retransmitido el bloque? ¿Para decirle que te deje crear de la nada 100BTC, cuando él sí que ha gastado miles de dólares en hardware? Ahí tenemos la importancia de la prueba de trabajo) Here she won’t know the participants. In fact most users will not even know the address of their vault or care about it. They will care their wallet address is logged locally with the vault to make payments to.

Hope that helps a bit Vitalik, it’s a pretty huge subject and although the rules are simple the number of personas is large and each has their own very confined measurable and cryptographically secured via a decentralised PKI type system as to identify them properly. So its a decent amount to get though.

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Thanks for the reply, David.

So, in a decentralized system nodes are controlled by someone, and that someone has the ability to download a patch which changes the node’s behavior. So I do agree that software defaults can place a moderately strong pressure in favor of certain behaviors, but ultimately software is just there to do what the user wants and if the user really wants to perform a different behavior for their own benefit then they can download and install a software patch to do so.

The cryptoeconomic philosophy that I generally ***ow is a bit more restrictive: complex systems of decentralized control can certainly produce very beautiful outcomes, but they are only truly stable if the rules are self-enforcing – ie. if the rules themselves specify incentives that make it in a user’s interests to act honestly and cooperatively.

If you don’t have such incentives, then your only alternative is to probably go the ripple/stellar route (or something similar, like http://128.199.188.22:1337/consensus.pdf ) and rely primarily on reputation.

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No worries. Thanks for the response, it’s not straight forward and none of us will know the outcomes, like Steve jobs said you can join the dots looking backwards not forwards (tontería para parecer cool y algo de falacia de autoridad, si es que al Jobs pudiese considerársele autoridad de algo), I try not to spray ddt on mossies . In any case the nodes may be owned by somebody but not controlled (Mentira, tal y como ya le ha explicado Buterin). Their action are directly managed by the network, so bad behaviour is spotted by the group who manage the node and outbound deterministic requests are accumulated and signature checked. So changing the vault code will simply miccionan you will have a defunct vault as it is de-ranked.(Le importa tres huevones lo que le acaba de decir Buterín, él sigue con la misma canción de que será la red la que se encargue de prevenir comportamientos como el que le ha especificado. El problema es que nunca dice cómo. Ya me dirás tú cómo huevones va a prevenir el que uno de los nodos convenza de actuar maliciosamente a los 31 restantes a los que se ha conectado, y que podrían perfectamente no tener ni un duro en hardware/safecoins invertidos en el sistema, a generar ingentes cantidades de Safecoins.)

I know your philosophy regarding incentives and hear it a lot from others, but I disagree with it on a couple of levels (not all). I think this is fine as I am not a game theory ***ower ( :: ) and certainly not bought into any Nash equilibrium theories as you seem to be (closer to) (Eso de la teoría de juegos debe ser cosas de malvados y egoístas capitalistas :XX: Lo que este tío ignora es que un sistema de este tipo sólo es fiable si, precisamente, se fundamenta en el egoísmo de sus actores) and that’s also fine. I believe you can have a complex system that has inherent incentives as in nature (otra vez con las pilinguis hormigas), why does the ant pick up the huge leaf, she could let others do it and just munch away. The discussion could take years and I still say vim is better than emacs kinda thing. Anyway the ant does it because it knows if everyone does their job they thrive, not through altruism but inbuilt logic (Y una cosa. La hormiga no es más que un simple tentáculo del verdadero e importante nodo: la reina. Pocas cosas hay más centralizadas en la naturaleza que un hormiguero. Ahí no hay necesidad de consenso ni de nada).

In decentralised systems there are a huge number of indirect incentives such as caching data, performing a tras*action for apparently no cost and there are also a huge number of ways to ensure correctness, if a node says 1 + 1 = 3 then others can tell it is rubbish (or sends wrong message to wrong node)(Falso y más que discutido ya. En redes abiertas, donde la topología de la red es desconocida, así como el lag durante las comunicaciones, llegar a este consenso es muchísmo más complejo y se hace necesaria la sincronía y los checkpoints), if it signs this then it can be reported to the nodes close to it with proof or bad performance. They will de-rank as they want to survive and the node loses out. To survive the node will want to not make such mistakes and will act responsibly or kicked out. There are a miriad of these rules and checks happening in real time. So incentives need not always be direct and certainly not always directly measurable. So you may say why cache you get nothing, then look much deeper and you actually get a lot from this apparent act of selflessness (it is actually selfish to do what is asked of you in the network, we spend a huge time making sure of that) but it’s not immediately measured and the user is not directly incentivised to do so. (osea, altruismo :XX: . ¿Cuántos sistemas conocéis que funcionen en base al altruismo?)

Then why report bad behaviour, there is no payment and again look much deeper, the payment is survival of the species (or version of the code ) (de nuevo, altruismo)

there are enormous threads going very deep into much of this on maidsafe.org and some papers (corre, ve y búscalos tú) on the site etc. so you can dive very deep into the network. I recommend Eric’s lectures on the network as there are things not immediately obvious in xor space and networks in particular. It keeps our uni people happy writing papers on it all and the security we have managed to achieve though it. So please feel free to dive in, it’s hugely interesting, but very different for sure. (Sí, y con suerte a ver si te pierdes y dejas de hacer "preguntas incómodas")

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