No, the nodes in the network were all still communicating with each other, the problem was that they were unable to form a global consensus on which transactions had occurred. A fragmented network would have experienced the same problem, but this was not a fragmented network.
That's semantics. The network was effectively cut into two partitions that could each sync amongst themselves but not with each other.
No, it was a problem with the abstract design, because the abstract design permits this sort of disagreement to happen regardless of whether the nodes can communicate with each other. This same problem could be caused deliberately by having nodes refuse to follow the block chain.
Only if the nodes that refused to follow the block chain all agreed to follow the same 'different block chain'. Which is what your proposed malicious attack with lots of computing power effectively entails, right?
No, as long as the threshold number of banks can communicate, the protocol would complete just fine; if somehow all the banks could be split from one another, the protocol would not run at all. That is the point of a threshold system: it works as long as the threshold number of parties is working together.
I misunderstood your threshold system as being a consensus system with a threshold for consensus to be reached. I didn't realize you meant a high availability cluster that shuts down when too many nodes aren't reachable.
I note also that the threshold would have to be greater than 50%, otherwise it would be possible for a cut network to theoretically continue to operate on both sides of the cut, which would be undesirable.
In any case, would the bank not still operate as a centralized authority? The whole network is down if a small number of 'bank' nodes are The bitcoin consensus system you point at as being attackable is only solvable by switching to a central authority?
You claim to have read Chaum's work, but you seem to have a lot of misconceptions about it...
I claim to have read some of it. And have been reading more as a result of this thread. I'm absolutely playing catch-up here. Thanks for clarifying points I've misunderstood.
Even if we were to accept such an argument -- and it is a very dubious argument -- all that says is that if the value of Bitcoin rises enough, the known attack will be profitable
But profitable and undetectable? Nonetheless I do concede that the attack vector is linear in difficulty relative to the size of the bitcoin network, not exponential. And its certainly at least theoretically possible gather that much computing power, vs say breaking 4096-RSA with what is available today.
The problem with Chaum's system is that it appears to rely on a central authority with respect to the banks, and is therefore at the whim of a "benevolent dictator for life".
Its also potentially fairly easy to disrupt and take down if a malicious / hostile group were to attempt to shut the 'bank' down. (thinking on the scale of the US government)
Being humble, but also believing that your views on how other people should live their lives are so righteous that others shouldn't even be able to decide for themselves, are mutually exclusive.
What about being so humble that one doesn't even consider one's own views on how people should live, and simply accepts the long accepted wisdom of the church as being greater than your own.
Sorry, we can argue that it may be 'stupid' or 'wrong' but its definitely not mutually exclusive with 'humility'.
My objection isn't to the expac itself. My objections are:
a) I don't like being told the xpac is a whole new game. It's not. It's an xpac. Its fine as an xpac. Lets not pretend its something its not.
b) Everyone knows out of the gate that SC2 was planned as having 2 xpacs to add campaigns for Zerg and Protoss. This smacks of dividing the game into 3 to sell expansions and make more money. Just how blantant they were about aside the fact remains that a lot of gamers were turned off by this.
When you approach game design like that, you are motivated to hold back things simply for the sake of selling the expansion later. Where the 'base game' is deliberately under-featured relative to what it "should have been". In some cases features of the expansion are actually present in the base game at shipping, just turned off. This is a turn off.
So I decided to wait until the xpacs were done. And I'll evaluate whether to buy the finished product once blizzard sells it as one.
Right I meant to include that. It doesn't change anything.
Hell, Blizzards own expansion to Diablo II contained the whole new barbarian city & dungeon area, new cinematics, new monsters, new bosses, the new beastmaster(?) class I can't recall what it was called, upgraded the graphics to support 800x600 up from 640x480, new item sets, and it added runes for sockets.
These days whole games are released with less content then old expansion packs. We're supposed to be grateful when a few new skins or multiplayer modes or maps show up as DLC, stuff that used to be offered in free patches for popular games along with the bug fixes.
Then blizzard comes along and releases a proper expansion pack which is fine. And then idiots start to argue that I'm supposed to treat it as a whole new game. Its not. Its just an xpac.
Me, I'll buy starcraft ii, maybe, once the protoss expac is out and its all bundled for one price. Or maybe not... I'm still pissed about the DRM.
No it wasn't. But people weren't trying to pretend that Broodwars was a whole new separate game either. It was an expansion pack. It was priced as one.
Does that help clarify things? Nobody but you is talking about disconnecting people from any network.
Except the issue here, the issue that this article was talking about is precisely that of a disconnected network. Due to what amounts to a compatibility problem between version 0.7 and 0.8 two networks have been created that can't synchronize. The 0.7 and 0.8 networks can't synchronize. The two networks can't talk to eachother.
And THAT is why double-spend became possible. Because the network was split. It was not a problem with the abstract design of bitcoin.
I'm not suggesting that there aren't any abstract theoretical vulnerabilities to bitcoin. I'm just arguing that THIS particular incident is not one of them.
Also false, it is possible to create a threshold/MPC system where multiple banks cooperate in the issuing/refreshing/verification process.
This sounds like it would run into the same issues as bitcoin just did if the multiple cooperating banks were for some reason unable to communicate. (e.g. some of them were upgraded, and others were not, and due to an oversight the two versions became unable to synchronize.) Then coins could be drawn from the same account at both banks, and the double spend would go undetected.
That is what happened with bitcoin.
That is where the real difference lies: it is not infeasible to gather enough computing power to attack Bitcoin
Is it economical though? If you can't steal more than it costs then feasibility isn't all that relevant.
I'm doubting that. When it come to horses it is not about GVW, it is more about balance and about the movement of the horses.
Right, smoothness is important, and you've got to drive extra "gently". I agree here. My point about GVW is that those tractors with double trailers hauling stuff like gasoline for example have similar constraints. You can't slam on the brakes, and liquid sloshing around has a lot of momentum on its own.
I've been saying all along that traffic lights/intersections are not configured for heavy vehicles
See, I'm disputing this. Traffic signal timing is set according to guidelines for stopping time and stopping distances under normal (but not optimal conditions). So the yellow length is calibrated for a heavy truck on a wet road for example. And a horse trailer should be fine with that.
and when municipalities begin to alter a system, game it, to make money, not safety, then it does not matter how fast or slow I drive, at some moment I can lose if I don't drive defensively. That is a lousy way to manage traffic and transportation.
I agree with all this, but do not think it is the norm. Most intersections don't have cameras and there is no revenue incentive at odds with the safety incentive. There are may more cameras that are configured with safety. There certainly are cases where the city has manipulated things for revenue, but I contend those are a distinct minority, and its usually a scandal when its revealed.
Give me a timer display and I can much better manage that intersection and not be an impediment to traffic.
Tell people exactly when its going to change, and people will be more inclined to accelerate I think, if they think they can make it. I'm skeptical that it would lead to better driving.
Out of curiosity, do you haul horses for competition? What kind of horses and what style of riding do you perform?
No. I used to work (quite a long ways back) at a boarding and training stables. My horse hauling was limited to customer service activities - transportation due to sale or for breeding and things like that. We worked a bit of everything; but it was probably mostly Quarter Horses and Appaloosas. Although we boarded an Arabian stud the whole time I was there. I remember him best. He was an asshole.:)
new multiplayer game modes, new units, new game replay features, new maps, new matchmaking, new grouping/clan features, new cinematics, and an entirely new full-length campaign....but it's just an expansion?!?
Yes.
It is telling that StarCraft 1 included 3 campaigns, and multiplayer, right out of the gate, one for each race. And the campaigns for starcraft 2 are not 3x as good nor 3x as long.
Finally, I fully expect some time after StarCraft's 3rd expansion is released, I'll be able to buy them as a single integrated "StarCraft 2: The whole game"
Please explain how this is any less of a full game than Assasin's Creed 2? Halo 2? Call of Duty Anything?
StarCraft's one integrated game in 3 pieces.
Assasin's Creed 2 is not integrated with 1 in any way.
Plus with starcraft 2 they designed it and what would be in it and each expac before the first game was released, for starters. I doubt they had Assassin's Creed mapped out before they started cutting code on Assassin's creed.
You make a good argument re "CoD anything" But then I'd say you were duped into over paying for rehashed sequels there.
Have you played the Starcraft 2: Wings of Liberty campaign? It is a full game all by itself. Starcraft 2: Wings of Libery + Starcraft 2: Heart of Swarm + Starcraft 2: Legacy of the Void, = 3 Games.
No. I count one game and two fairly expensive expansion packs. They include a few extra units, some multiplayer tweaks, and a map pack.
Most triple-A companies would charge you $60 per game which comes out to $180 for the series. Assuming the final game is also $40, Blizzard is charging you $140.
Most successful attacks are "hard to see" until someone manages to pull them off.
But this doesn't even suggest an attack vector, because a node can only send/receive information to other nodes. It can't prevent two other nodes from talking to eachother, and as long as it can do that it can't corrupt the system.
In the case of online clearing, this is obvious: the bank will just not make a deposit to the seller's account.
And if the bank cannot be reached because the network was bisected? An online clearing system only works if there is communication.
In the case of an offline protocol (de-anonymizing), double spending is possible only as long as nobody brings their money to the bank; once the double-spending is identified, the attacker is removed from the system entirely. Violating these properties requires computational power that is exponential in a security parameter, whereas the work required to use the system is polynomial in that parameter.
Again, if part of the system can't reach the bank for some reason, then double spending is possible.
If you can prevent communication between a party and 'the issuing bank' then you can double spend. I fail to see how this is any different?
How will you know which nodes are good and which are bad?
Presumably because you can verify the blockchain for yourself.
Violating these properties requires computational power that is exponential in a security parameter, whereas the work required to use the system is polynomial in that parameter.
I don't think so. You just need to corrupt/takedown 'the bank' and you can do all sorts of evil with all the coins it issued. Single point of failure, as opposed to needing to corrupt >50% of the network to overwhelm its consensus.
I don't see how that is anywhere near the $4 for a request given that most responses I deal with now are done electronically
[...] a somewhat exorbitant price [...]
which, incidentally, is what keeps me and a surprisingly large number of attorneys in business.
Wait? Are you an attorney? And your quibbling over a $4 service fee as 'exorbitant'? $4 will buy me around 45 seconds with my last lawyer and all he did was sign some filled out templates and boilerplate his assistant prepared for him to transfer a couple property titles? I think he cost me close $600.
Would it be cheaper to hire you to file a FOIA request? What would you charge?
And yet, all of the jury's decisions still stand in principle.
True; the trial judge has so far decided not to overturn the jury verdict of her own case. No one is really THAT surprised by that.
However
a) The actual appeals haven't even really started yet. You know, in the appeals courts, where the trial judge isn't the one making decisions.
b) The patents themselves may fall (that at least some will fall is almost inevitable), and if they do the jury's decisions and awards related to them will be mooted.
And some will still get larger, simply by the fact that Samsung keeps selling infringing products.
Until the appeals and patent cases are over that is a flight of pure fantasy.
That being said, yes, malice is the problem: an attacker is going to send bad messages, desynchronize messages, modify messages, and so forth.
And none of that matters. Because the good nodes can still communicate with eachother, and sync directly with eachother, and validate everything for themselves.
The idea of 'bad nodes' aren't the problem here. The problem is that that one class of good nodes can't communicate with another class of good nodes. Both of them deemed good, both of them are using the official bitcoin software. That they can't sync is a real problem, but it's hard to see how a network of malicious nodes could replicate the issue.
A malicious node, or even a network of malicious nodes can't prevent to good nodes from communicating.
There are already reports of people taking advantage of the forked block chain to double spend their money.
That is precisely because the network was inadvertently forked, and you have good nodes on both forks, and the wallets exist on both.
This is essentially the same situation you would have if you had a bank account with a large multinational and suddenly all links between N.A and Eurasia were severed. Your account information was replicated between the multi-nationals redundant servers on both continents before the split and you'd be able to spend the money from your account on both continents because the transactions on one continent could not get synchronized with the other.
Presumably eventually they would sync, and your overdraft would be detected. But what if the break was permanent? Then the double-spend would go undetected permanently.
Now wrapping this up by addressing this:
read Chaum's work.
I've read some of it, perhaps I'm missing something you think is relevant, and if so please point it out. But my understanding of Chaum's double-spending protocol doesn't prevent doublespending, it just allows eventual identification of the party that did it. But that wouldn't help here, because the network is effectively bisected and something you doublespend on one side can't propagate to the other, so the doublespend will never be resolved.
If this can be caused by an accident, then it might also be caused deliberately by a motivated attacker.
Only if he can permanently bisect the network. Short of a nation severing the links, or the protocol goof that happened in this case. I don't see it happening. No amount of malicious nodes spouting garbage is going to prevent two good nodes from talking to each other.
All your malicious nodes can refuse to sync with me all they like. I'll sync with a good one.
*Note: I don't use bitcoin. I am not a proponent of bitcoin.*
Let's put it this way: an attacker might deliberately create incompatibilities between nodes in Bitcoin by using some kind of malware; trigger this when enough nodes are infected and you give yourself the perfect opportunity to double spend.
So does anything that segregates the network. China flips a switch, and severs all links to the outside world permanently, and you essentially have 2 independent bitcoin networks going forwards.
My argument was simply that the issue that led to the fork isn't because the security system design inherently relied on some particular implementation detail.
It merely relied on the abstract concept of communication between nodes. If the network is bisected for any reason and one segment permanently can't sync with the other you run into this problem.
If Bitcoin cannot survive that sort of deviation, then Bitcoin is not secure enough for monetary transactions, even if you are talking about a third or even half the nodes in the network being malicious.
That's a bit over the top. I'm not sure any currency is secure enough for monetary transactions according to the standard you appear to demand. You do realize people counterfeit cash a lot easier than bitcoins, right?
And credit cards? They are just as reliant on being able to communicate. If the network goes down the payment method is either worthless, or merchants go back to taking imprints and waiting for the network to come back up to complete them. What if the network doesn't come back up... ?
What would happen to unposted VISA transactions authorized but not completed in a country that decided to go isolationist and sever phone and internet links to the outside world.
In general, a multiparty computation system (a category that includes all digital cash systems, Bitcoin included) needs to be able to maintain its security properties even when some parties are corrupted.
The problem isn't corruption or malice. The problem is communication. Corruption can be detected because any node can validate everything for itself. But if the network is bisected it's not corrupt, its merely divided into 2 independent networks that can't talk to eachother.
This is a cryptosystem whose security depends on specific implementation details.
Not quite. This is a cryptosystem whose compatibility was limited by specific implementation details.
To put it another way, imagine if instead of the database implementation, it was the CPU architecture that determined the security of the system. As long as everyone uses x86, it is fine, but if a few people start using ARM or PowerPC the system "forks." What differentiates that hypothetical scenario from the database issue?
Lets say x86 uses 8bit bytes, while ARM uses 10bit bytes. The x86 version of my cryptosystem works, the spec is defined in terms of 'bytes' as the smallest chunk of data. Everything is fine.
Then someone ports it to ARM. The ARM version is also built to spec. They start it up. It syncronizes with x86 versions no problem, and then it passes the data onwards to other ARM and x86 systems, also no problem. On ARM systems, the upper 2 bits go unsused, and when data is passed to an x86 system they are stripped off.
Then someone creates some new data on the arm version, and houston, we have a problem. The new data created on ARM is using the upper 2 bits, and although the new data syncs fine with other ARM units, it fails when syncing back to x86 units.
The crypto-system isn't reliant on 8 bit bytes in the abstract. The system, in the abstract, will work with any size byte. But nobody actually specified the byte size when doing the implementation. And it worked well enough, even cross architecture for a while before anyone noticed the issue.
Clearly the fix is to either update the 8bit system to cope with 10bits, restrict the 10bit system to working with 8 bits, or add in some meta data to describe what byte size the data is, and some bit-packing standards for moving the data between architectures.
But there is nothing wrong with the crypto system in the abstract. Nor is there anything wrong with the 'security'.
The award was reduced based on the fact that the jury used an impermissible legal theory to calculate them. That is a straight up reduction.
An additional trial was also ordered to calculate damages in cases where the judge couldn't simply strike them. The portion that falls under that may yet go up or down, but smart money would be on down; since the judge believes the same impermissible legal theory was used to calculate those damages too, but she doesn't have the information needed to break the total down into what parts were permissible and what wasn't.
All that doesn't even consider the various underlying patents that are under pressure and a number of which have already been preliminarily ruled invalid. If / when they fall the damages will fall even further.
Tagging if you don't have an account is pretty meaningless because the tags aren't attached to your account. Its just a name attached to that picture.
Facebook made it easy for people to "tag" you -
Last I heard, it was quite a bit easier to tag friends on your contact list then non-users who don't have accounts. So the odds of being tagged go down if you don't have an account.
Now not having a Facebook account is treated by HR departments as suspicious behavior. [...] So best move is to have one that's effectively empty, and turn all privacy settings down to the most private.
And then HR just assumes you have another account you aren't showing them.
The assumption is that it is likely to get back to you even if someone does record you. For every person who gets to be "Internet famous" through having their epic fail shared on YouTube there are thousands, maybe even millions, of others who are relegated to complete obscurity and I like those odds.
Those odds are changing. With automatic facial recognition and geo-location tagging, and even the recently announced automatic recognition by what clothes you wear, the odds that it will get back to you and people you know will increase enormously.
I also keep my nose clean...
Yes, that can be a problem too;)
'Man caught picking nose' is a pretty well represented youtube genre. Couple that with automatic facial-recognition, geolocation, etc...
and so lower my chances further by remaining an unattractive target.
And while that may be true for you. What about the slice of society we call "pretty women"? Do they deserve the level of scrutiny and exposure that will be heaped on them?
Guys wandering around staring at womens chests all day, then uploading them to a site that will inevitably exist for them to collaborate on, with facial recgonition and geo-location to make identifying and linking images taken at different times by different users? Sure maybe they won't be following you around... but your wife? your daughter? your niece?
Some handy little database where you upload a picture of that pretty legal assisant at work and get all the google glass images of her... relaxing at the beach, out jogging, working out at the gym, picking her nose at a bus stop, topless on vacation in Spain.
Right now, all that took place in public. But the odds of them all being caught on camera, and all being uploaded to the internet, and all being linked together is virtually zero. You can safely "play those odds" right now.
But in the future you are embracing? The odds of all that being on the internet and linked together is virtually inevitable. Anyone who knows your name, or any picture of you can theoretically locate everything that anyone else has ever seen of you.
You've never driven a horse trailer loaded with two large horses
I have. And the solution is simple. Drive slightly below the posted speed limit; or in many cases, simply driving at the posted limit instead 'with traffic' somewhat above it.
if/when it goes to yellow for I still need to maintain traffic speed.
No. You don't. You can drive slower if necessary. If a tractor trailer with a GVW of 80,000 lbs can meet the regulations for stopping times and stopping distances then so can you.
If you can't then your vehicle / trailer / cargo weight combination is unsafe to drive at the speeds you are driving. Get a new truck, and/or new trailer with better brakes.
If only sports cars are able to stop at a particular light raise it with the city engineering department. They do get it wrong from time to time. But more often then not, you are simply driving too fast for the conditions or your vehicle isn't safe to operate at that speed.
Yet my experience is that speeders tend to go over 20% faster than the posted speed limit.
And when the speed limit is 25mph, 20% faster is a reckless 30mph? Like in a school zone at 4:57? When three minutes later the proper limit is 30mph?
In that case, it's not a scam.
There's a highway near hear (full on highway, wide lanes, divider separating east/west traffic, retaining wall on one side, railroad on the other. No intersections, no sidewalks. No pedestrians, no reason for pedestrians -- that sort of highway.) Speed limit is 50mph; not unreasonable, and if anything a bit low. People usually go 55 or so. But that's not even the problem.
The problem bit is that near the west end it joins up with the rest of the road network. There's an intersection with lights, and beyond that intersection there's access to businesses, there's sidewalks, etc. It becomes a more residential road. And the limit is 30mph.
The problem is that the transition from 50 to 30mph takes place about a 3/4mile east of the intersection. So traffic is legally supposed to slow down 30mph on a full blown highway.
In reality traffic tends to ease off the gas at a 1/4 mile before the intersection and is going ~30mph before it reaches the lights; or is stopped if the lights are red of course.
It works, the intersection is quite safe, the traffic is moving at a safe speed by the time its in the city.
So where did they set up the speed cameras? Just past the sign changing the limit to 30mph, in the middle of the highway, nearly a mile out of the city. Where everyone was pretty much going 55+. 55+ in a 30 those reckless assholes!
perfectly within their rights to use highly efficient technology to catch those law breakers.
And the citizens are perfectly in their rights to reject it. Here, for example, photo radar was banned.
The problem was not "speed related accidents" perpetrated by "law breakers". The just looked for those little gaps where the speed limit didn't really make any sense, and then exploited the average citizen for profit.
so just let 6pm be sundown and 6am be sunup, no matter where you are or what time of year it is
You do realize that the number of daylight hours varies over the year, and by latitude right?
In winter at even medium latitutes (northern contiguous united states) there might only be 7 or so hours of daylight a day. So 6am and 6pm would be 7hours apart and then the time from 6pm to 6am would be 17hrs long? So the length of an hour would change depending on whether it was day or night?
Go far enough north and there is no sun up in winter. At all. How does your system of time work if there is no rising sun for a full month?
One thing a lot of pro abortion people put on their blinders about is that many women are forced or "strongly coerced" to have abortions by parents, boyfriends, bosses that knocked them up, etc. These women can be led through the process without ever really knowing what is going to happen to them physically and psychologially until it's irreversable.
That argument cuts both ways.
And the pro-life crowd isn't generally going around proposing people considering abortion need more unbiased education on what is going on. They're taking a very different tack.
I know a woman that [...] I've also known women that [...]
Yet you don't know any women traumatized by raising a baby conceived in incest or rape. None traumatized by raising a baby conceived while a young teen and not remotely emotionally or financially able to handle the burden of caring for it. None who have had their family ripped apart by the having to not only to try and cope with the fallout from infidelity but also an unwanted child?
so there is noone that can convince me that abortion is an emotionally void process that should just be mechanically performed with no councelling at all.
I've met plenty of pro-life advocates who think "counseling" is just shorthand for "sessions of intense religious dogma to generate guilt alternating with videos of 3rd world abortions gone wrong to create revulsion, disgust, and fear.", you know "counseling".
In all seriousness though, I've never met a pro-choice advocate who ever suggested it was or should be a mechanical operation devoid of emotion*, and that it should be done without councelling.
(* although thinking of it as such as much as possible is a legitimate coping mechanism for the real emotional anguish one goes through.)
However, if you want us to pay for it, then we will fight it tooth and nail.
Because the girl that got raped should foot the bill?
I'm with you in terms of abortion-as-birth-control; but I don't think the majority of abortion is done as simple birth control*; they ARE pretty major emotional events that most people do put a LOT of thought into; despite the cynical pro-life characterizations of pro-choice women who get up in the morning, decide to have an abortion, and then spend more time picking what shoes to wear. That's just not an accurate picture of a pro-choice person.
* - and I think this is where state supported birth control makes a lot of sense. We have plenty of people; and we should be giving the necessary tools to the people who don't want to create more of them. Not denying them, and certainly not guilting them over using them... but that's a whole other can of worms.
But in the end I do see much advantage to bringing unwanted children into the world.
Slashdot Mirror
No, the nodes in the network were all still communicating with each other, the problem was that they were unable to form a global consensus on which transactions had occurred. A fragmented network would have experienced the same problem, but this was not a fragmented network.
That's semantics. The network was effectively cut into two partitions that could each sync amongst themselves but not with each other.
No, it was a problem with the abstract design, because the abstract design permits this sort of disagreement to happen regardless of whether the nodes can communicate with each other. This same problem could be caused deliberately by having nodes refuse to follow the block chain.
Only if the nodes that refused to follow the block chain all agreed to follow the same 'different block chain'. Which is what your proposed malicious attack with lots of computing power effectively entails, right?
No, as long as the threshold number of banks can communicate, the protocol would complete just fine; if somehow all the banks could be split from one another, the protocol would not run at all. That is the point of a threshold system: it works as long as the threshold number of parties is working together.
I misunderstood your threshold system as being a consensus system with a threshold for consensus to be reached. I didn't realize you meant a high availability cluster that shuts down when too many nodes aren't reachable.
I note also that the threshold would have to be greater than 50%, otherwise it would be possible for a cut network to theoretically continue to operate on both sides of the cut, which would be undesirable.
In any case, would the bank not still operate as a centralized authority? The whole network is down if a small number of 'bank' nodes are The bitcoin consensus system you point at as being attackable is only solvable by switching to a central authority?
You claim to have read Chaum's work, but you seem to have a lot of misconceptions about it...
I claim to have read some of it. And have been reading more as a result of this thread. I'm absolutely playing catch-up here. Thanks for clarifying points I've misunderstood.
Even if we were to accept such an argument -- and it is a very dubious argument -- all that says is that if the value of Bitcoin rises enough, the known attack will be profitable
But profitable and undetectable? Nonetheless I do concede that the attack vector is linear in difficulty relative to the size of the bitcoin network, not exponential. And its certainly at least theoretically possible gather that much computing power, vs say breaking 4096-RSA with what is available today.
The problem with Chaum's system is that it appears to rely on a central authority with respect to the banks, and is therefore at the whim of a "benevolent dictator for life".
Its also potentially fairly easy to disrupt and take down if a malicious / hostile group were to attempt to shut the 'bank' down. (thinking on the scale of the US government)
Being humble, but also believing that your views on how other people should live their lives are so righteous that others shouldn't even be able to decide for themselves, are mutually exclusive.
What about being so humble that one doesn't even consider one's own views on how people should live, and simply accepts the long accepted wisdom of the church as being greater than your own.
Sorry, we can argue that it may be 'stupid' or 'wrong' but its definitely not mutually exclusive with 'humility'.
My objection isn't to the expac itself. My objections are:
a) I don't like being told the xpac is a whole new game. It's not. It's an xpac. Its fine as an xpac. Lets not pretend its something its not.
b) Everyone knows out of the gate that SC2 was planned as having 2 xpacs to add campaigns for Zerg and Protoss. This smacks of dividing the game into 3 to sell expansions and make more money. Just how blantant they were about aside the fact remains that a lot of gamers were turned off by this.
When you approach game design like that, you are motivated to hold back things simply for the sake of selling the expansion later. Where the 'base game' is deliberately under-featured relative to what it "should have been". In some cases features of the expansion are actually present in the base game at shipping, just turned off. This is a turn off.
So I decided to wait until the xpacs were done. And I'll evaluate whether to buy the finished product once blizzard sells it as one.
And a full length single player campaign.
Right I meant to include that. It doesn't change anything.
Hell, Blizzards own expansion to Diablo II contained the whole new barbarian city & dungeon area, new cinematics, new monsters, new bosses, the new beastmaster(?) class I can't recall what it was called, upgraded the graphics to support 800x600 up from 640x480, new item sets, and it added runes for sockets.
These days whole games are released with less content then old expansion packs. We're supposed to be grateful when a few new skins or multiplayer modes or maps show up as DLC, stuff that used to be offered in free patches for popular games along with the bug fixes.
Then blizzard comes along and releases a proper expansion pack which is fine. And then idiots start to argue that I'm supposed to treat it as a whole new game. Its not. Its just an xpac.
Me, I'll buy starcraft ii, maybe, once the protoss expac is out and its all bundled for one price. Or maybe not... I'm still pissed about the DRM.
And this is different from Brood Wars?
No it wasn't. But people weren't trying to pretend that Broodwars was a whole new separate game either. It was an expansion pack. It was priced as one.
Does that help clarify things? Nobody but you is talking about disconnecting people from any network.
Except the issue here, the issue that this article was talking about is precisely that of a disconnected network. Due to what amounts to a compatibility problem between version 0.7 and 0.8 two networks have been created that can't synchronize. The 0.7 and 0.8 networks can't synchronize. The two networks can't talk to eachother.
And THAT is why double-spend became possible. Because the network was split. It was not a problem with the abstract design of bitcoin.
I'm not suggesting that there aren't any abstract theoretical vulnerabilities to bitcoin. I'm just arguing that THIS particular incident is not one of them.
Also false, it is possible to create a threshold/MPC system where multiple banks cooperate in the issuing/refreshing/verification process.
This sounds like it would run into the same issues as bitcoin just did if the multiple cooperating banks were for some reason unable to communicate. (e.g. some of them were upgraded, and others were not, and due to an oversight the two versions became unable to synchronize.) Then coins could be drawn from the same account at both banks, and the double spend would go undetected.
That is what happened with bitcoin.
That is where the real difference lies: it is not infeasible to gather enough computing power to attack Bitcoin
Is it economical though? If you can't steal more than it costs then feasibility isn't all that relevant.
I'm doubting that. When it come to horses it is not about GVW, it is more about balance and about the movement of the horses.
Right, smoothness is important, and you've got to drive extra "gently". I agree here. My point about GVW is that those tractors with double trailers hauling stuff like gasoline for example have similar constraints. You can't slam on the brakes, and liquid sloshing around has a lot of momentum on its own.
I've been saying all along that traffic lights/intersections are not configured for heavy vehicles
See, I'm disputing this. Traffic signal timing is set according to guidelines for stopping time and stopping distances under normal (but not optimal conditions). So the yellow length is calibrated for a heavy truck on a wet road for example. And a horse trailer should be fine with that.
and when municipalities begin to alter a system, game it, to make money, not safety, then it does not matter how fast or slow I drive, at some moment I can lose if I don't drive defensively. That is a lousy way to manage traffic and transportation.
I agree with all this, but do not think it is the norm. Most intersections don't have cameras and there is no revenue incentive at odds with the safety incentive. There are may more cameras that are configured with safety. There certainly are cases where the city has manipulated things for revenue, but I contend those are a distinct minority, and its usually a scandal when its revealed.
Give me a timer display and I can much better manage that intersection and not be an impediment to traffic.
Tell people exactly when its going to change, and people will be more inclined to accelerate I think, if they think they can make it. I'm skeptical that it would lead to better driving.
Out of curiosity, do you haul horses for competition? What kind of horses and what style of riding do you perform?
No. I used to work (quite a long ways back) at a boarding and training stables. My horse hauling was limited to customer service activities - transportation due to sale or for breeding and things like that. We worked a bit of everything; but it was probably mostly Quarter Horses and Appaloosas. Although we boarded an Arabian stud the whole time I was there. I remember him best. He was an asshole. :)
new multiplayer game modes, new units, new game replay features, new maps, new matchmaking, new grouping/clan features, new cinematics, and an entirely new full-length campaign....but it's just an expansion?!?
Yes.
It is telling that StarCraft 1 included 3 campaigns, and multiplayer, right out of the gate, one for each race. And the campaigns for starcraft 2 are not 3x as good nor 3x as long.
Finally, I fully expect some time after StarCraft's 3rd expansion is released, I'll be able to buy them as a single integrated "StarCraft 2: The whole game"
Please explain how this is any less of a full game than Assasin's Creed 2? Halo 2? Call of Duty Anything?
StarCraft's one integrated game in 3 pieces.
Assasin's Creed 2 is not integrated with 1 in any way.
Plus with starcraft 2 they designed it and what would be in it and each expac before the first game was released, for starters. I doubt they had Assassin's Creed mapped out before they started cutting code on Assassin's creed.
You make a good argument re "CoD anything" But then I'd say you were duped into over paying for rehashed sequels there.
Have you played the Starcraft 2: Wings of Liberty campaign? It is a full game all by itself. Starcraft 2: Wings of Libery + Starcraft 2: Heart of Swarm + Starcraft 2: Legacy of the Void, = 3 Games.
No. I count one game and two fairly expensive expansion packs. They include a few extra units, some multiplayer tweaks, and a map pack.
Most triple-A companies would charge you $60 per game which comes out to $180 for the series. Assuming the final game is also $40, Blizzard is charging you $140.
How much koolaid did you drink?
Most successful attacks are "hard to see" until someone manages to pull them off.
But this doesn't even suggest an attack vector, because a node can only send/receive information to other nodes. It can't prevent two other nodes from talking to eachother, and as long as it can do that it can't corrupt the system.
In the case of online clearing, this is obvious: the bank will just not make a deposit to the seller's account.
And if the bank cannot be reached because the network was bisected? An online clearing system only works if there is communication.
In the case of an offline protocol (de-anonymizing), double spending is possible only as long as nobody brings their money to the bank; once the double-spending is identified, the attacker is removed from the system entirely. Violating these properties requires computational power that is exponential in a security parameter, whereas the work required to use the system is polynomial in that parameter.
Again, if part of the system can't reach the bank for some reason, then double spending is possible.
If you can prevent communication between a party and 'the issuing bank' then you can double spend. I fail to see how this is any different?
How will you know which nodes are good and which are bad?
Presumably because you can verify the blockchain for yourself.
Violating these properties requires computational power that is exponential in a security parameter, whereas the work required to use the system is polynomial in that parameter.
I don't think so. You just need to corrupt/takedown 'the bank' and you can do all sorts of evil with all the coins it issued. Single point of failure, as opposed to needing to corrupt >50% of the network to overwhelm its consensus.
I don't see how that is anywhere near the $4 for a request given that most responses I deal with now are done electronically
[...]
a somewhat exorbitant price
[...]
which, incidentally, is what keeps me and a surprisingly large number of attorneys in business.
Wait? Are you an attorney? And your quibbling over a $4 service fee as 'exorbitant'? $4 will buy me around 45 seconds with my last lawyer and all he did was sign some filled out templates and boilerplate his assistant prepared for him to transfer a couple property titles? I think he cost me close $600.
Would it be cheaper to hire you to file a FOIA request? What would you charge?
And yet, all of the jury's decisions still stand in principle.
True; the trial judge has so far decided not to overturn the jury verdict of her own case. No one is really THAT surprised by that.
However
a) The actual appeals haven't even really started yet. You know, in the appeals courts, where the trial judge isn't the one making decisions.
b) The patents themselves may fall (that at least some will fall is almost inevitable), and if they do the jury's decisions and awards related to them will be mooted.
And some will still get larger, simply by the fact that Samsung keeps selling infringing products.
Until the appeals and patent cases are over that is a flight of pure fantasy.
That being said, yes, malice is the problem: an attacker is going to send bad messages, desynchronize messages, modify messages, and so forth.
And none of that matters. Because the good nodes can still communicate with eachother, and sync directly with eachother, and validate everything for themselves.
The idea of 'bad nodes' aren't the problem here. The problem is that that one class of good nodes can't communicate with another class of good nodes. Both of them deemed good, both of them are using the official bitcoin software. That they can't sync is a real problem, but it's hard to see how a network of malicious nodes could replicate the issue.
A malicious node, or even a network of malicious nodes can't prevent to good nodes from communicating.
There are already reports of people taking advantage of the forked block chain to double spend their money.
That is precisely because the network was inadvertently forked, and you have good nodes on both forks, and the wallets exist on both.
This is essentially the same situation you would have if you had a bank account with a large multinational and suddenly all links between N.A and Eurasia were severed. Your account information was replicated between the multi-nationals redundant servers on both continents before the split and you'd be able to spend the money from your account on both continents because the transactions on one continent could not get synchronized with the other.
Presumably eventually they would sync, and your overdraft would be detected. But what if the break was permanent? Then the double-spend would go undetected permanently.
Now wrapping this up by addressing this:
read Chaum's work.
I've read some of it, perhaps I'm missing something you think is relevant, and if so please point it out. But my understanding of Chaum's double-spending protocol doesn't prevent doublespending, it just allows eventual identification of the party that did it. But that wouldn't help here, because the network is effectively bisected and something you doublespend on one side can't propagate to the other, so the doublespend will never be resolved.
If this can be caused by an accident, then it might also be caused deliberately by a motivated attacker.
Only if he can permanently bisect the network. Short of a nation severing the links, or the protocol goof that happened in this case. I don't see it happening. No amount of malicious nodes spouting garbage is going to prevent two good nodes from talking to each other.
All your malicious nodes can refuse to sync with me all they like. I'll sync with a good one.
*Note: I don't use bitcoin. I am not a proponent of bitcoin.*
Let's put it this way: an attacker might deliberately create incompatibilities between nodes in Bitcoin by using some kind of malware; trigger this when enough nodes are infected and you give yourself the perfect opportunity to double spend.
So does anything that segregates the network. China flips a switch, and severs all links to the outside world permanently, and you essentially have 2 independent bitcoin networks going forwards.
My argument was simply that the issue that led to the fork isn't because the security system design inherently relied on some particular implementation detail.
It merely relied on the abstract concept of communication between nodes. If the network is bisected for any reason and one segment permanently can't sync with the other you run into this problem.
If Bitcoin cannot survive that sort of deviation, then Bitcoin is not secure enough for monetary transactions, even if you are talking about a third or even half the nodes in the network being malicious.
That's a bit over the top. I'm not sure any currency is secure enough for monetary transactions according to the standard you appear to demand. You do realize people counterfeit cash a lot easier than bitcoins, right?
And credit cards? They are just as reliant on being able to communicate. If the network goes down the payment method is either worthless, or merchants go back to taking imprints and waiting for the network to come back up to complete them. What if the network doesn't come back up... ?
What would happen to unposted VISA transactions authorized but not completed in a country that decided to go isolationist and sever phone and internet links to the outside world.
In general, a multiparty computation system (a category that includes all digital cash systems, Bitcoin included) needs to be able to maintain its security properties even when some parties are corrupted.
The problem isn't corruption or malice. The problem is communication. Corruption can be detected because any node can validate everything for itself. But if the network is bisected it's not corrupt, its merely divided into 2 independent networks that can't talk to eachother.
This is a cryptosystem whose security depends on specific implementation details.
Not quite. This is a cryptosystem whose compatibility was limited by specific implementation details.
To put it another way, imagine if instead of the database implementation, it was the CPU architecture that determined the security of the system. As long as everyone uses x86, it is fine, but if a few people start using ARM or PowerPC the system "forks." What differentiates that hypothetical scenario from the database issue?
Lets say x86 uses 8bit bytes, while ARM uses 10bit bytes. The x86 version of my cryptosystem works, the spec is defined in terms of 'bytes' as the smallest chunk of data. Everything is fine.
Then someone ports it to ARM. The ARM version is also built to spec. They start it up. It syncronizes with x86 versions no problem, and then it passes the data onwards to other ARM and x86 systems, also no problem. On ARM systems, the upper 2 bits go unsused, and when data is passed to an x86 system they are stripped off.
Then someone creates some new data on the arm version, and houston, we have a problem. The new data created on ARM is using the upper 2 bits, and although the new data syncs fine with other ARM units, it fails when syncing back to x86 units.
The crypto-system isn't reliant on 8 bit bytes in the abstract. The system, in the abstract, will work with any size byte. But nobody actually specified the byte size when doing the implementation. And it worked well enough, even cross architecture for a while before anyone noticed the issue.
Clearly the fix is to either update the 8bit system to cope with 10bits, restrict the 10bit system to working with 8 bits, or add in some meta data to describe what byte size the data is, and some bit-packing standards for moving the data between architectures.
But there is nothing wrong with the crypto system in the abstract. Nor is there anything wrong with the 'security'.
The database issue is essentially the same thing.
The award was reduced based on the fact that the jury used an impermissible legal theory to calculate them. That is a straight up reduction.
An additional trial was also ordered to calculate damages in cases where the judge couldn't simply strike them. The portion that falls under that may yet go up or down, but smart money would be on down; since the judge believes the same impermissible legal theory was used to calculate those damages too, but she doesn't have the information needed to break the total down into what parts were permissible and what wasn't.
All that doesn't even consider the various underlying patents that are under pressure and a number of which have already been preliminarily ruled invalid. If / when they fall the damages will fall even further.
Having won the last lawsuit to the tune of $1B
The award has already been chopped almost in half, and the case hasn't even gotten to appeals yet.
http://www.macgasm.net/2013/03/01/judge-koh-cuts-400-million-from-apple-samsung-suit/
I personally doubt there will be much of anything left of that award in the end.
Tagging if you don't have an account is pretty meaningless because the tags aren't attached to your account. Its just a name attached to that picture.
Facebook made it easy for people to "tag" you -
Last I heard, it was quite a bit easier to tag friends on your contact list then non-users who don't have accounts. So the odds of being tagged go down if you don't have an account.
Now not having a Facebook account is treated by HR departments as suspicious behavior. [...] So best move is to have one that's effectively empty, and turn all privacy settings down to the most private.
And then HR just assumes you have another account you aren't showing them.
The assumption is that it is likely to get back to you even if someone does record you. For every person who gets to be "Internet famous" through having their epic fail shared on YouTube there are thousands, maybe even millions, of others who are relegated to complete obscurity and I like those odds.
Those odds are changing. With automatic facial recognition and geo-location tagging, and even the recently announced automatic recognition by what clothes you wear, the odds that it will get back to you and people you know will increase enormously.
I also keep my nose clean...
Yes, that can be a problem too ;)
'Man caught picking nose' is a pretty well represented youtube genre. Couple that with automatic facial-recognition, geolocation, etc...
and so lower my chances further by remaining an unattractive target.
And while that may be true for you. What about the slice of society we call "pretty women"? Do they deserve the level of scrutiny and exposure that will be heaped on them?
Guys wandering around staring at womens chests all day, then uploading them to a site that will inevitably exist for them to collaborate on, with facial recgonition and geo-location to make identifying and linking images taken at different times by different users? Sure maybe they won't be following you around... but your wife? your daughter? your niece?
Some handy little database where you upload a picture of that pretty legal assisant at work and get all the google glass images of her... relaxing at the beach, out jogging, working out at the gym, picking her nose at a bus stop, topless on vacation in Spain.
Right now, all that took place in public. But the odds of them all being caught on camera, and all being uploaded to the internet, and all being linked together is virtually zero. You can safely "play those odds" right now.
But in the future you are embracing? The odds of all that being on the internet and linked together is virtually inevitable. Anyone who knows your name, or any picture of you can theoretically locate everything that anyone else has ever seen of you.
You've never driven a horse trailer loaded with two large horses
I have. And the solution is simple. Drive slightly below the posted speed limit; or in many cases, simply driving at the posted limit instead 'with traffic' somewhat above it.
if/when it goes to yellow for I still need to maintain traffic speed.
No. You don't. You can drive slower if necessary. If a tractor trailer with a GVW of 80,000 lbs can meet the regulations for stopping times and stopping distances then so can you.
If you can't then your vehicle / trailer / cargo weight combination is unsafe to drive at the speeds you are driving. Get a new truck, and/or new trailer with better brakes.
If only sports cars are able to stop at a particular light raise it with the city engineering department. They do get it wrong from time to time. But more often then not, you are simply driving too fast for the conditions or your vehicle isn't safe to operate at that speed.
Yet my experience is that speeders tend to go over 20% faster than the posted speed limit.
And when the speed limit is 25mph, 20% faster is a reckless 30mph? Like in a school zone at 4:57? When three minutes later the proper limit is 30mph?
In that case, it's not a scam.
There's a highway near hear (full on highway, wide lanes, divider separating east/west traffic, retaining wall on one side, railroad on the other. No intersections, no sidewalks. No pedestrians, no reason for pedestrians -- that sort of highway.) Speed limit is 50mph; not unreasonable, and if anything a bit low. People usually go 55 or so. But that's not even the problem.
The problem bit is that near the west end it joins up with the rest of the road network. There's an intersection with lights, and beyond that intersection there's access to businesses, there's sidewalks, etc. It becomes a more residential road. And the limit is 30mph.
The problem is that the transition from 50 to 30mph takes place about a 3/4mile east of the intersection. So traffic is legally supposed to slow down 30mph on a full blown highway.
In reality traffic tends to ease off the gas at a 1/4 mile before the intersection and is going ~30mph before it reaches the lights; or is stopped if the lights are red of course.
It works, the intersection is quite safe, the traffic is moving at a safe speed by the time its in the city.
So where did they set up the speed cameras? Just past the sign changing the limit to 30mph, in the middle of the highway, nearly a mile out of the city. Where everyone was pretty much going 55+. 55+ in a 30 those reckless assholes!
perfectly within their rights to use highly efficient technology to catch those law breakers.
And the citizens are perfectly in their rights to reject it. Here, for example, photo radar was banned.
The problem was not "speed related accidents" perpetrated by "law breakers". The just looked for those little gaps where the speed limit didn't really make any sense, and then exploited the average citizen for profit.
People are not going to record your stupid dalliances because (and this may shock you): NO ONE CARES.
You haven't used youtube have you? Its just one big compilation of other people's fail caught on video.
People do care. They collect it. They compile it. They set it to music and share it with their friends.
so just let 6pm be sundown and 6am be sunup, no matter where you are or what time of year it is
You do realize that the number of daylight hours varies over the year, and by latitude right?
In winter at even medium latitutes (northern contiguous united states) there might only be 7 or so hours of daylight a day. So 6am and 6pm would be 7hours apart and then the time from 6pm to 6am would be 17hrs long? So the length of an hour would change depending on whether it was day or night?
Go far enough north and there is no sun up in winter. At all. How does your system of time work if there is no rising sun for a full month?
But in the end I do see much advantage to bringing unwanted children into the world.
"do" should be "don't"
sheesh.
One thing a lot of pro abortion people put on their blinders about is that many women are forced or "strongly coerced" to have abortions by parents, boyfriends, bosses that knocked them up, etc. These women can be led through the process without ever really knowing what is going to happen to them physically and psychologially until it's irreversable.
That argument cuts both ways.
And the pro-life crowd isn't generally going around proposing people considering abortion need more unbiased education on what is going on. They're taking a very different tack.
I know a woman that [...] I've also known women that [...]
Yet you don't know any women traumatized by raising a baby conceived in incest or rape. None traumatized by raising a baby conceived while a young teen and not remotely emotionally or financially able to handle the burden of caring for it. None who have had their family ripped apart by the having to not only to try and cope with the fallout from infidelity but also an unwanted child?
so there is noone that can convince me that abortion is an emotionally void process that should just be mechanically performed with no councelling at all.
I've met plenty of pro-life advocates who think "counseling" is just shorthand for "sessions of intense religious dogma to generate guilt alternating with videos of 3rd world abortions gone wrong to create revulsion, disgust, and fear.", you know "counseling".
In all seriousness though, I've never met a pro-choice advocate who ever suggested it was or should be a mechanical operation devoid of emotion*, and that it should be done without councelling.
(* although thinking of it as such as much as possible is a legitimate coping mechanism for the real emotional anguish one goes through.)
However, if you want us to pay for it, then we will fight it tooth and nail.
Because the girl that got raped should foot the bill?
I'm with you in terms of abortion-as-birth-control; but I don't think the majority of abortion is done as simple birth control*; they ARE pretty major emotional events that most people do put a LOT of thought into; despite the cynical pro-life characterizations of pro-choice women who get up in the morning, decide to have an abortion, and then spend more time picking what shoes to wear. That's just not an accurate picture of a pro-choice person.
* - and I think this is where state supported birth control makes a lot of sense. We have plenty of people; and we should be giving the necessary tools to the people who don't want to create more of them. Not denying them, and certainly not guilting them over using them... but that's a whole other can of worms.
But in the end I do see much advantage to bringing unwanted children into the world.