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4501  Local / Produits et services / Re: btcex.com: Français on: April 30, 2011, 04:44:26 AM
In english maybe? Most of the site is still in english, such as the lobby. Mainly, the help page, the most relevant it appears, is still in english.
4502  Bitcoin / Bitcoin Discussion / Re: Next parities to watch on: April 29, 2011, 01:38:39 AM
Come on, hyperinflation!

Zimbabwe style?
4503  Local / Produits et services / Re: btcex.com: Français on: April 29, 2011, 01:31:24 AM
Il y a pas grand chose en francais =O
4504  Local / Discussions générales et utilisation du Bitcoin / Re: Je n'ai pas tout compris... on: April 29, 2011, 01:26:07 AM
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Visiblement, on peut envoyer des pièces dans un porte-monnaie qui n'a existé qu'un court instant (ok les pièces ce perdent) le volume monétaire risque finalement de se réduire au fil du temps...
Je peut donc recevoir un payement alors que mon pc est éteint (le réseau est témoin). Que contient exactement un porte-monnaie ?

Le volume monétaire étant fixe, la monnaie est par definition déflationnaire. En gros plus le systeme est adopté et plus les pièces sont "perdue", plus les pièces en circulation ont de valeur. Le porte monnaie contient des paires d'adresse: une publique et une privée. La publique permet de recevoir des pièces, la privée permet d'utiliser les pièces recues sous la clé publique. Le porte monnaie ne contient que les clés. Quand le client recoit les transactions, il permet de controller les pièces qui ont été signées avec les clés publiques présentes dans le porte monnaie.

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Si on compare les bitcoins aux billets, les banques centrales disparaissent (l'inflation n'est donc plus contrôlée) mais ça ne changera rien sur l'existence des banques qui pourront prêter plus qu'elles ne possèdent.

Les Bitcoins sont en effet décentraliser, il n'y a pas d'entité, telle un banque centrale, qui controle la masse monétaire en circulation n'y emet de taux directeur principale ou légalise la reserve fractionnaire. Bien que ce système ne s'oppose pas a l'existence même des banques, l'absence de banque centrale va séverement limiter la capacité d'une banque à utiliser les dépots de ses client pour offrir des prêts à d'autre, tout en prétendant avoir l'intégralité des dêpots a disposition des dêpositaires.

Aussi le fait que l'historique de toute les transactions est publique et que les dépositaires connaisent l'adresse Bitcoin sur laquelle ils ont déposé leur argent, il devient assez tedieux (mais pas impossible) pour la banque de prêter cet argent sans quelqu'un puisse le déceler.

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Y a t'il une description du monde que l'on pourrait imaginer si les bitcoins sont largement adoptés ?

Dans le cas de la crise de 2008, le secteur financier, à l'origine de la crise, n'aurait pas de banque centrale pour lui preter des milliards d'argent publique afin de le sauver de sa propre erreur.
4505  Bitcoin / Mining / Re: Do we want oblivious mining pool shares? on: April 28, 2011, 10:00:59 PM
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1. The block header will include 3 extra fields, which for now I'll call simply A, B and C.
2. B is a hash of A.
3. The block hash will be a hash of all the usual stuff and also B.
4. C is a hash of the concatenation of the block hash and A.
5. For the block to be valid: Instead of requiring that the block hash is less than (1 / (2^32 * difficulty)), it is required that the block
hash is less than (1 / 2^32) and C is less than (1 / difficulty).
So solo miners choose anything for A (maybe all zeros) and hash it once to find B. Then they calculate hashes normally but with B added. When they find a difficulty-1 hash they calculate C to extra check if it satisfies the real difficulty.
For pools, the operators choose A and keep it secret, but hand out B as part of the getwork. The participants can calculate the block hash and if it satisfies difficulty-1 they submit it as a share, but they don't know if it satisfies real difficulty because they don't know A and thus can't calculate C. The operator can of course make the verification, and at round end A is published as part of the block and participants can verify that none of their winning shares were rejected.

Ok, I've reread this part.

I like the idea but it doesn't seem to me there is a need to modify the protocol for the operator to produce B and send it over. Afaik, pool miners aren't directly part of the Bitcoin network, their connection and their work is with the pool only, so only that part could be modified. Also, what is to stop a miner with the actual system from finding a full difficulty solution and modifying his miner to submit this result as a soloer. Wouldn't that kind of exploit be much more devastating and feasible?
4506  Bitcoin / Mining / Re: Do we want oblivious mining pool shares? on: April 28, 2011, 08:13:44 PM
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It just needs to switch to a different pool which I think takes about a second.

On 20 or so computers? The attack is only worth it when you have a sizeable portion of the hashing power of a big pool. Consider most of those mining rigs don't even have a monitor plugged to them. To render this attack profitable would require a good amount of coding necessary to automatize the switching.
Of course. If he's invested in 20+ computers, he can invest in coding the automation.

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Who's "his"? The cheater can create several accounts and use an anonymization service to hide his IP.
It's quite easy for the pool operator to establish a ratio between between total shares submitted per block vs reward. Any worker used for that attack can be automatically identified and have its rewards denied.
Good point, though there will be false positives.
My main point is that if you make the protocol immune to such attacks, the operator doesn't need to deal with such nonsense and the participants don't risk being hurt by the countermeasures.

I understand your concern. Mine is that I'd rather any attack that is not directly related to the Bitcoin protocol to be first realistically evaluated by those targeted, and a proper attempt at countering it delivered. Only if the counter fails should there be a discussion about integrating solutions directly to the project code. I think also this threads lacks discussion about the downside of implementing oblivious shares, to which I have sadly nothing to contribute.

Lastly, I wonder if oblivious shares would be the hard counter to your exploit. I don't understand how it would prevent the attacker from verifying his own produced shares against the target block on his own. Or would that cost him too much hashing speed?
4507  Bitcoin / Mining / Re: Do we want oblivious mining pool shares? on: April 28, 2011, 07:19:30 PM
I don't understand what you mean by "troll the pool".

Let me rephrase: You'll be a minor annoyance to the pool, attempting once in a long while to make the pool lose money.

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Why would a mining rig need to be reset?

 I was trying to imply that the hashing power spent on solo mining with the switched portion of your mining speed would be essential "wasted". Many big miners prefer soloing to avoid pool fees. The exploit would be much more efficient if you keep your "ambush" mining power in a proportional pool while setting up, which represents another portion of steady earning (the pool fee the soloers avoid) that you would be risking.

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It just needs to switch to a different pool which I think takes about a second.

On 20 or so computers? The attack is only worth it when you have a sizeable portion of the hashing power of a big pool. Consider most of those mining rigs don't even have a monitor plugged to them. To render this attack profitable would require a good amount of coding necessary to automatize the switching.

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Who's "his"? The cheater can create several accounts and use an anonymization service to hide his IP.

It's quite easy for the pool operator to establish a ratio between between total shares submitted per block vs reward. Any worker used for that attack can be automatically identified and have its rewards denied.
4508  Local / Discussions générales et utilisation du Bitcoin / Re: Je n'ai pas tout compris... on: April 28, 2011, 06:07:12 PM
Bonjour, je vais essayer de repondre point par point:

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- La quantité totale de monnaies sera, à terme, constante.

Oui.

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-La puissance de calcul est simplement un moyen permettant de répartir cette monnaie aux utilisateurs durant les premières années.

La puissance de calcul permet de vérifier la validité des transaction. Ces transactions sont entassé en blocs (~4000 transaction max par bloc, ~6 bloc par heure) que les "mineurs" (ce qui fournisse la puissance de calcul) procédent. Le mineur qui resout un bloc recoit une recompense sous la forme de nouvelle piece, jusqu'a ce que toute les pieces aient été distribuée. La puissance de calcul donc, protege le réseau contres les fausses transaction, et ce qui la fournisse recoivent des Bitcoins en retour du service. La recompense en Bitcoin incite les utilisateurs a fournir de la puissance de calcul, ce qui secure le reseau tout en permettant de disseminer le Bitcoin d'une maniere qui permet au reseau de prosperer.

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- Ce que l'on appelle le réseau, c'est plusieurs (une majorité ?) programmes client.
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En gros, oui. Chaque client qui se connecte au reseau recoit la chaine de blocs, verifie les solutions trouvé par les mineurs, et partage la chaine.

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- Chaque porte-monnaies est un fichier crypté identifié de façon unique par le réseau.

Pas exactement. Le porte monnaie n'est pas cripter, il faut donc prendre ses precautions soit meme. Chaque transaction signe les pieces envoyées d'une clé publique. Cette cle publique est crée par le client, qui detient la clé soeur, elle privée. Quand le client lit la chaine de blocs, il permet de controller les piéces dont la clé publique fait parti des paires de clé privée-publique presentes dans le porte monnaie.

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- Les pièces et transactions existent uniquement parce qu'elles sont reconnues comme telles par le réseau.

En effet.

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- La cryptographie rend difficile l'envoi de monnaies depuis une adresse que l'on ne possède pas.

C'est l'idée, oui.

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- Que se passe t'il si j'envoie des bitcoins sur une adresse inexistante ?

Je doute que ca marche. Cependant, si des Bitcoins sont signé avec une clé publique dont la clé privée a été perdu, les piéces sont perdues

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- Est-ce raisonnable de répartir l'argent en fonction de la puissance de calcul ? Et surtout, n'y a t'il pas un risque que des petits malins s'approprie une grande part dès les premières années ?

La puissance de calcul n'est pas gratuite, ni l'electricité qu'elle necessite. Plus on investi, plus on est recompensé. Quand au petit malin, ils ont pris un plus grand risque que ce qui se sont presenté en dernier, une fois que le Bitcoin est bien installé et valoriser, ils meritent donc une meilleure recompense.

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- Quel en est le but ? Une banque pourrait très bien reproduire le même schéma qu'avec nos monnaies actuelles. (monnaies fiduciaires/scripturales)

Une banque aurait un conlfit d'interet, elle manipulerait la monnaie a sont avantage et au detriment des usagés. L'aspect du Bitcoin est qu'il est decentraliser, donc personne ne peut s'amuser avec sa valeur artificiellement.
4509  Bitcoin / Bitcoin Discussion / Re: Gavin will visit the CIA on: April 28, 2011, 05:25:39 PM
What I'm doing is saying that in this one narrow capacity (accepting a speaker fee for his "time" for a speech given in his representative capacity), he is not representing his community properly.  You're not arguing against that; you seem to be saying I shouldn't even say it, but there's no basis for that.  This part of the discussion is part of the evaluation of whether he is representing "properly" in this particular instance.

I'm arguing against the fact that some here think giving this speech hereby makes him a representative of the community. It's like saying a developer at Blizzard giving a speech about his work with MMORPGs is representing the wow player base oO.

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I'm going to give a presentation about Bitcoin at CIA headquarters in June at an emerging technologies conference for the US intelligence community.

Correct me if I'm wrong, but he'll be attending a technological conference. What he'll be presenting is the technological aspect of Bitcoin. I don't acknowledge the existence of a community under the terms I think you are defining it, but for the sake of the argument, I'll admit to it. Now, if community there is, its motive is economical, not technological. The technology is merely the tool that allows for the economical aspect to exist. This is why I see Gavin as only giving a speech on his experience with the crypto/p2p/mining thing, not discussing that fact that the big majority of users here hate the fed or have anarchist tendencies. I see the fee as legitimate compensation for sharing his knowledge.

Your analogy strikes me as calling Mark Zuckerberg a representative of the Facebook community, in which case that community would have died long ago, given his character. I got dozens more analogy like this if you'd like.
4510  Bitcoin / Bitcoin Discussion / Re: Gavin will visit the CIA on: April 28, 2011, 05:01:57 PM
Doesn't Gavin already live on the east cost of the US?  I thought he was only originally from Australia.
Yep, I live in Amherst, Massachusetts; my family moved to the US when I was 5 years old.

I will be visiting Australia (Sydney for a couple of days then Tasmania for a couple weeks then Cairns for a week or two) in July.

My bad.

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I'm glad for him that others of you are satisfied with him as a leader


Leader under what terms? One of the goals of this project is to break part of the coercive control government has over the economy, so it is not in the governmental sense. Then do you mean in the representative sense? If so, then representatives that can't represent properly will eventually be replaced. Now let the guy take his shot.
4511  Bitcoin / Bitcoin Discussion / Re: Gavin will visit the CIA on: April 28, 2011, 04:03:52 PM
That essentially covers the traveling fair from Australia to East coast USA, so yeah.

Doesn't Gavin already live on the east cost of the US?  I thought he was only originally from Australia.

I read somewhere that he lives in Australia but I can be wrong.
4512  Bitcoin / Bitcoin Discussion / Re: Gavin will visit the CIA on: April 28, 2011, 03:52:50 PM
I don't understand this talk of community. To mine and use Bitcoins doesn't entitle anyone to any kind of responsibility towards any other Bitcoin user. There is also no fee or responsibility to endorse in order to start using Bitcoins. There is thus not such a thing as a hierarchy in what is simply a group of people going about their business using the same commodity. It's like saying a gold miner who's invited to speak about his digging experience should share his compensation fee with every other person using gold in the nation.
4513  Bitcoin / Mining / Re: Anti-mining movement with their own agenda READ ON on: April 28, 2011, 02:30:26 PM
I think you're right, I've only met one person called Vladimir in person and he was Russian. Therefore I think this Vladimir may also be Russian. The only Russian government agency I can think of is the KGB. That means Vladimir is a KGB agent. You know it makes sense Cheesy.

He'll make soup out of your fingers, for the muddaland!
4514  Bitcoin / Bitcoin Discussion / Re: Gavin will visit the CIA on: April 28, 2011, 02:27:15 PM
As for honorariums, well, it takes time, they are paying him for his time. It's not a big amount actually to cover travel expenses and time. If it were half that I probably wouldn't go myself, except maybe from curiosity.

That essentially covers the traveling fair from Australia to East coast USA, so yeah.

What makes me uncomfortable is that the CIA is keeping tabs on a 12 million USD community... I thought the USA was involved in enough conflicts in the world to have intelligence resources to spend on a drop of water in the ocean.
4515  Bitcoin / Mining / Re: Anti-mining movement with their own agenda READ ON on: April 28, 2011, 02:18:20 PM
Doesn't matter how many people are mining. If the difficulty goes up, the price goes up as well negating the impact of difficulty increase. Only thing bad is more pollution to Earth.

No. There is no linear nor consistent correlation between price and difficulty. One new miner joining doesn't guaranty one new buyer on Gox.
4516  Bitcoin / Mining / Re: Do we want oblivious mining pool shares? on: April 28, 2011, 02:08:41 PM
Would that really work? To hold 25% of the network hashrate means you're expected to solve one out of every 4 blocks faster than any other miner, but that doesn't mean you can sit on the solution eternally.
The point is that on Slush's pool the newest shares have the highest value, so if you can hold it back for 1 minute you would increase the expected payout by several percent. If somebody else solves it first you don't really loose anything unless it's the pool you moved the other miners away from.

If I understand this thread properly, we are talking about pool users exploiting/damaging the pool reward, in this case I see 2 situations:

1) Small contribution: If you're only running, let's say, 1~2 Gh/s, the chances are ridiculously low for you to find that full difficulty solution. To be sitting at the computer all day waiting for it to happen once a week is beyond tedious. You could always modify your miner to hold the share, but at this point you're just trying to troll the pool, and it's not all that efficient.

2) Big contribution: You're like 10% of the pool. Now you have to assume you have consequent hashing power contributed to another pool or mining solo. This isn't impossible, but limited to a few individuals with stellar hashing power. Who's walking around with 30~40 Gh/s and pool mining hmm? Besides Gusti, I can't name anyone. At this point, holding out on every full difficulty solution you found long enough for you to move all your hashing power on slush's pool (there are no other who realistically suffers from this attack) is a huge risk. It'll take certainly more than a minute, there are several mining rigs that need to be reset for the purpose of the exploit.

What you are risking here, technically, is to try and increase your payout on a few blocks, at the risk of losing your original payout if a pool finds the solution you are withholding, all this considering you need to move all your hashing power to slush's pool and let it beef up your reward to a seizable profit under 10 minutes (If no one beats you to it under 10 minutes. Given the way the network is built, this is more than likely)

If you ask me, it is not only tedious, but has low chance of success, and a high risk of losing your "fair" reward.

Also any user with a big contribution can be easily monitored by the pool owner. If you see his reported hashing speed double up once a while a few minutes before a block is completed, it'll speak for itself.
4517  Bitcoin / Bitcoin Discussion / Re: Good stuffs that came out of bitcoin on: April 28, 2011, 12:37:19 PM
deflation, anyone?
4518  Bitcoin / Mining / Re: Do we want oblivious mining pool shares? on: April 28, 2011, 11:25:13 AM
It's the other way around. You take all of your miners off other pools and into this pool. After you've generated a hefty amount of shares for this pool, you submit the winning share and get a nice reward for all these shares.

Would that really work? To hold 25% of the network hashrate means you're expected to solve one out of every 4 blocks faster than any other miner, but that doesn't mean you can sit on the solution eternally. Chances are a couple minutes later another pool/miner will have found the solution to that block and submitted it. The only thing I see this method accomplish is to gimp the targetted pool to the benefit of other pools, so I don't think the "Lie in Wait" part is feasible.
4519  Bitcoin / Bitcoin Discussion / Re: bitcoin crack on: April 28, 2011, 01:18:21 AM
Assuming it happens for no apparent reason I can probably get a lot for my wife.

Time to get myself one of those.
4520  Bitcoin / Bitcoin Discussion / Re: Gavin will visit the CIA on: April 27, 2011, 07:07:31 PM
Should start a donation thread for the eventual casket hurr durr
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