Search content
Sort by

Showing 20 of 253 results by fastandfurious
Post
Topic
Board Development & Technical Discussion
Re: Proposal: Pre-emptive measures against 51% attacks
by
fastandfurious
on 17/05/2012, 06:59:27 UTC
Asking again because I think this is very important, especially because of the 25 BTC change at the end of the year, many legit miners will leave and the bots will remain, thus making Bitcoin vulnerable to a 51 % attack.  Gavin and others, any progress or information on this?
Post
Topic
Board Bitcoin Discussion
Re: Tainted coins - Who dictates that a coin is tainted?
by
fastandfurious
on 14/05/2012, 02:44:29 UTC
Not necessarily...  If someone gave you a pile of fiat that was splattered with some bright colored dye or paint, such as what happens when a bank robber flees the scene of the crime and opens their bag of ill-gotten bills only to find an exploding dye canister going off in their face and all over the bills, would you really expect a bank or merchant to accept those "tainted" bills?  This is the fiat equivalent to "tainted" Bitcoin.

I haven't personally decided if I support the idea of "tainting" bitcoin yet, but this would be an example of the real-world equivalent.
No, that's totally different because this "taint" is visually obvious and can't appear on a bill while it's sitting in your pocket. A better analogy would be if the FBI regularly published a list of serial numbers of currency that would no longer be honored. Banks would refuse to accept bills on the list, and soon so would grocery stores and so on. That hundred dollar bill you got from the bank, now sitting in your wallet, could appear on that list at any time because the person who deposited it at the bank right before you withdrew might have stolen it.

Think about what using currency would be like in such a world. Could you even have ATM machines? In fact, it would be the death of cash -- forcing people to use cash only for small amounts of money they could afford to lose. Such "tainting", if it hit the Bitcoin world, would similarly be the death of Bitcoin if it caught on in any significant way.


+1
Post
Topic
Board Bitcoin Discussion
Re: Tainted coins - Who dictates that a coin is tainted?
by
fastandfurious
on 13/05/2012, 14:16:26 UTC
If someone is giving me fiat money, I know that I can spend that money as easliy as I got it. The same thing should be with Bitcoin, so how are we going to handle with this issue?

Not necessarily...  If someone gave you a pile of fiat that was splattered with some bright colored dye or paint, such as what happens when a bank robber flees the scene of the crime and opens their bag of ill-gotten bills only to find an exploding dye canister going off in their face and all over the bills, would you really expect a bank or merchant to accept those "tainted" bills?  This is the fiat equivalent to "tainted" Bitcoin.

I haven't personally decided if I support the idea of "tainting" bitcoin yet, but this would be an example of the real-world equivalent.

I have travelled to over 40 countries in my life and I have exchanged fiat curenncy to goods or another currency for probalby (guessing here) more than 10 000 times, everytime this transactions has gone smoothly, maybe I have been a lucky guy, buy I think we all have similar experinces with fiat.
Post
Topic
Board Bitcoin Discussion
Re: Tainted coins - Who decides what is a tainted coin?
by
fastandfurious
on 13/05/2012, 07:35:34 UTC
"BTW this issue has been discussed at length on this forum before (with a little searching you will discover a number of threads)."

And what is the conclusion, do we have a clarification of the way we are handling with this issue?

If not, as I have understood it we should have this topic very active until we have a answer to it. Mt.gox and other exchanges should also participate. Living in a grey zone is a joke long term.
Post
Topic
Board Bitcoin Discussion
Topic OP
Tainted coins - Who dictates that a coin is tainted?
by
fastandfurious
on 13/05/2012, 07:18:04 UTC
This is one of Bitcoins biggest questions right now, what is a tainted coin? It seems that it already are some tainted coins out there that for example Mt.Gox is not allowing to be traded with at their exchange, how does one know if they have some tainted coins in their wallet? And also who dictates if a coin is tainted or not?

This community should have a very clear answer to this questions, no one serious will invest in this Economy in the long run without a clarification and Bitcoin will just attract small players and hackers.

If someone is giving me fiat money, I know that I can spend that money as easliy as I got it. The same thing should be with Bitcoin, so how are we going to handle with this issue?
Post
Topic
Board Development & Technical Discussion
Re: Proposal: Pre-emptive measures against 51% attacks
by
fastandfurious
on 04/04/2012, 15:56:41 UTC
Any progress on this proposal?
Post
Topic
Board Development & Technical Discussion
Re: Proposal: Pre-emptive measures against 51% attacks
by
fastandfurious
on 24/03/2012, 18:08:54 UTC
Would it be possible to shift the entire mining process to a system similar to p2pool that would include a signature based on it's own tree?  Then just accept blocks that are also signed by THE decentralized mining pool so everyone has to use it.  I guess it's a "one true way" approach.

I'm loosely thinking about something like what p2pmining.com is attempting to do.  Perhaps existing pools would submit blocks through the main p2p pool where they would be signed, maybe paying a small fee that is distributed to miners in the process.  Basically all miners/the masses would work together in a single p2p mining pool as gatekeepers to the actual blockchain.  External pools could still exist but would need to still submit blocks through the main p2p mining pool and pay a small fee of each blockreward to be signed and accepted.  I know there would be a lot of complexities to work out, I'm just thinking out loud and wondering if it would even be possible and what the potential problems would be.

Very interesting.
Post
Topic
Board Development & Technical Discussion
Re: Proposal: Pre-emptive measures against 51% attacks
by
fastandfurious
on 23/03/2012, 10:52:44 UTC
I started experimenting with user-defined checkpoints (-checkpoint=height,hash multiarg, and 'addcheckpoint ' RPC call) but stopped when higher priority issues came up.

It seems to me that type of low-level mechanism is the right way to go; checkpointing is a good low-level way of identifying which chain you think is "the" chain. And making it command-line/RPC configurable means we don't all have to agree on One True Way of deciding what the right blockchain aught to be; cunicula can write some code that implements proof-of-stake and then tie it into bitcoin/bitcoind using -blocknotify.  etotheipi can write some code that scans the blockchain for well-known miner signatures (or asks miners directly if they produced a new block), etc.

If your argument is "But Gavin, if core Bitcoin doesn't support One True Way of doing I'll never be able to convince miners to do it my way!" then I'd say you need to better express to them how the benefits of your proposal outweigh the costs.

Any update on this, will this get implemented in the near future (less than a couple of months)?
Post
Topic
Board Speculation
Re: Bye Bye $4's
by
fastandfurious
on 20/03/2012, 11:19:25 UTC
I suspect that at least some of this drop was caused by Mt Gox having bank issues in Hong Kong.



Exactly what kind of issues?
Post
Topic
Board Development & Technical Discussion
Re: Proposal: Pre-emptive measures against 51% attacks
by
fastandfurious
on 18/03/2012, 09:52:14 UTC
Was thinking a bit... about what would happen in the event of a 51% attack.

Imagine a 51% attack against Bitcoin that was begun in secret, to create a large alternate chain that simply reversed a very large number of blocks, and persistently prevented any transactions from confirming.  The chain would be published all at once as a surprise and would propagate across the network faster than any worm.

Even if many of us could deal with that, the news would say "BITCOIN HACKED", that would be the end of Bitcoin as we know it, at least for a short while, until we all scattered around and figured out what to do about it.  

The problem with a 51% attack done this way is its effects would be sudden and instant.  The repair would be several days while the developers figure out what to do, and several more while the bugs get fixed, and plenty more time while people download it, repair their block chains, backport the patch to their customized clients, get back in business... meanwhile, we'd have lots of angry miners whose mining work on the fake chain got reversed, etc...

I would like to propose a couple simple things now relating to checkpointing so that the solution is known and the disaster preventable all the way in advance.

Basically, what I am proposing is that a) trusted entities put signed checkpoints in the block chain - which are nothing more than assertions that "I have seen the block with hash x", and b) that the client have some sort of list of trusted public keys (modifiable by power users, but otherwise pre-seeded by client authors) so that trusted parties can be recognized but also removed if needed.

Signatures would appear periodically in blocks, which would be part of real or dummy transactions.  MtGox, for example, may occasionally initiate a transaction to itself (or embed in one of its payout transactions) a signature referencing the hash of a prior block, simply to say "I saw this".  MtGox need not sign every single block - since each signature acknowledges all blocks before it, there will be other signers participating, and the scheme is mainly targeted at attacks on 6+ blocks, the signatures could be done three or ten or any other reasonable number of blocks apart.

Mining pools would do the same except would likely use the coinbase transaction as the location for their signature.

Very simply - if I as a client have block X, which I know has been seen by MtGox, TradeHill, and a dozen mining pools and trusted parties... I can quickly and confidently reject block Y which purports to replace block X with a higher proof of work.

To implement this proposal, all that would need to happen is:
  • client gets a mini database to track trusted public keys, possibly kept in wallet.dat, but pre-seeded from hardcoded values in the client
  • client gets an RPC call to modify this database for power users
  • definition of "standard transaction" amended to include one that packs an OP_DROPped signature so that trusted parties can count on their stamps of approval being relayed
  • the logic for handling chain reorgs more than 3 blocks deep is revised such that blocks known to have been seen by a majority of the trusted crowd are impervious to being preempted by blocks that have not.

The vast majority of client users would be using the default list of trusted public keys and would be unlikely to modify it, so the onus would be on the authors of clients to appropriately judge who belongs to be on the list.  The idea of allowing the client author to update the list remotely isn't out of the question - a suggestion probably not appropriate for the reference client - but entirely plausible for smaller-time clients whose users could just quit using if the authors were up to shenanigans.

Casascius, I really don't think people understand how important it is to understand what your proposal is saying. For me when thinking about it, it says exactly what will be the doom of Bitcoin it this in some way wont get implemented in the future.

I am sure that your proposal of checkpoints of trusted entities is pretty much unnecessary when the total market cap of Bitcoin is $100M or even as much as $1 Billion, but the question is what this does if and when the market cap is nearing $10 Billion? Bitcoin is going head to head against central banks, politicians, all fiat money and the status quo of everything that the average joe knows and accepts about rules of finance and economics in the world. When something like Bitcoin comes in and changes this, trust me, let me repeal that, TRUST ME the establishment will do anything to prevent Bitcoin to get to higher adoption. And one way of doing this is a 51 % attack, it is very effective and for them probably not that expensive way of destroying the hole Bitcoin project.

Just some thoughts. The trusted entities that you choose is probably good ones, but I think they are very few in number. Maybe it should be as much as 349 trusted entities /persons (we have to see BTC as a global phenomenon and because of that 349 or even more trusted entities are necessary) and there should be a voting system that chooses these persons, like once every year or two like a parliament. Everyone should have the opportunity to get elected, and the election can take place on the Bitcoin.org site. You vote with your BTC, Every BTC in the wallet that it is sent from is one vote, and you send one satoshi as a way of showing the person/entities you want to vote for. All entities tells the Bitcoin community who they are and what they stand for.

Also one more big point is that this checkpoints of this trusted entities is not something that is hard coded in the client, the way it works right now will be enough with hard coding with every new client the development team releases, BUT when and if there is a 51 % attack then we should have this emergency checkpoint system come in in to work and only then when there is a 51 % attack that he Bitcoin community didn't know about and recognize as a 51 % attack this parliament will get activated and the checkpoints of this parliament will be the ones that will get hard coded in to the client. This is a way of telling any government that any attack will not get Bitcoin on the knees.

Any thoughts?  
Post
Topic
Board Bitcoin Discussion
Re: How do you go short position in bitcoinica?
by
fastandfurious
on 06/01/2012, 00:44:26 UTC
Just contact Zhou and he will do a manual withdrawal for you, exchanging it to BTC is pretty expensive, so just contact Zhou and he will handle it.
Post
Topic
Board Speculation
Re: Margin Trading and Options Soon on MTGox
by
fastandfurious
on 20/12/2011, 00:03:37 UTC
Interesting. Where did you see that?
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 19/12/2011, 08:14:13 UTC
Read what I wrote in the first post. I have never said that Bitcoin is a ponzi.
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 19/12/2011, 07:33:00 UTC
Do you guys believe me now? Smiley

Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 18/12/2011, 19:53:53 UTC
Bitcoin is (very) volatile in it self, so this is just to funny, and it is one more thing that shows that this market is in some way manipulated.

Lets see how many more days they can keep the price this stable.

I don't see any inherent reason that bitcoins should be so volatile. Until recently, the price was very volatile, but what has happened is that rather than one person dropping the price one day by selling and another person spiking the price the next by buying, there are now more speculators, or the ones there just have more money at their disposal, and so the person selling bunches today gives to the speculators, and the person buying bunches tomorrow takes from the speculators and the price remains pretty stable.

You are making the wrong assumption, this market is manipulated. This is how I see it, the price should be higher than 3.50 USD right now if everything was played as it normally is if you look at the order depth and knowing that it is very hard to get under 3 USD right now. Someone is building up this manipulation, I think they have bought a lot of bitcoins, they really don't want the price to go down, but at the same time they understand fundamentals so they are selling at 3.20 USD and over, by doing this and have a lot of buy order in the market, they are forcing this fake or manipulated stable behavior. At the same time they don't lose that much UDS or BTC, so they are playing the game of manipulating well (right now). The only way they can lose is if someone will sell massively in to this (fake) bid walls, then they will panic as always and the inflation and panic after that will make it worse. The thing is that we are at 3 USD and the downside is not that big. I think they have by doing this fundamentally put BTC around 1 dollar higher than it should be, but it is at a cost and right now we are printing 2,6 million BTC more until Dec 2012, so they will  probably lose (again) in the end. Time is on the downside.
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 18/12/2011, 18:34:12 UTC
Bitcoin is (very) volatile in it self, so this is just to funny, and it is one more thing that shows that this market is in some way manipulated.

Lets see how many more days they can keep the price this stable.
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 13/12/2011, 08:33:08 UTC
high inflation? 25% APR is tiny considering how new bitcoin is.  Most disruptive technologies fail. But the ones that don't fail, usually grow a lot faster than 25% APR in the first few years.  

Bitcoin today is not that tiny. The total market cap of Bitcoin is around 24 million dollars at this exchange rate. And the inflation is 33% not 25%.
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 13/12/2011, 07:44:19 UTC

Smiley

But the original name is Duracell. That is the name we use in Sweden.

http://en.wikipedia.org/wiki/Duracell_Bunny
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 13/12/2011, 07:35:09 UTC
Yes, the inflation rate is still very high, somewhere close to 25% APR right now.  About this time next year it will be around 12.5%, but will suddenly drop to about 6.25% and resume it's slow decent for another 4 years.  For any increases in the BTCUSD exchange rate to be sustainable, there must be a growth rate in the economy that exceeds that inflation rate.  For the first 18 months, there was no bitcoin economy to speak off, so for the past 18 months maintaining an economic growth rate well in excess of the inflation rate has been relatively easy starting from near zero.  However, as the economy grows larger and the monetary base grows larger, the difficulty in maintaining such levels of economic growth increases.  I still don't believe that an economic growth rate well in excess of the inflation rate is improbable, and that we are as likely to see a return to steady exchange value growth as the general perception in the strength of bitcoin increases while the general mistrust in national fiat currencies also increases.  There will always be noise in the signal to deal with, however.

It is higher then that, it is around 33 % annual inflation rate today. And your conclusion is right as well, good to see people here are able to see the whole picture.
Post
Topic
Board Speculation
Re: You guys don't get it - Bitcoin will act like a Ponzi scheme until Dec 2012
by
fastandfurious
on 13/12/2011, 07:31:10 UTC
It's not a Ponzi (a single fraudster faking returns) at all.  It's much closer to a pyramid (people buying in then desperately trying to get more people to buy in), though still different in a couple important ways.

As for the rest of it, that's basically what I've been saying for a while.  Until there's a lot more commerce, it's overvalued.  But everyone's so hung up on making sure they don't get left out when people start getting rich.

This won't end in 12/2012.  That will just raise the bar a little by decreasing inflation.  The fact that there's excess currency supply (currently hoarded) will eventually make itself known as people begin putting it back on the market.

This is why I occasionally toss around RevCoin (Exchange-stabilized low-inflation coins), GEM (generation-stabilized low-inflation coins), EnCoin (a more complicated system)...  All of which will undermine the wild "We're gonna be rich!" speculation, and leave pricing to market-based immediate needs and relatively short-term economic speculation.

Revalin, right, pyramid scheme is more the right word. Thanks for that. Also, I think it will end in Dec 2012. The inflation rate is so much lower then, so it will have a big impact.