Slashdot Mirror
Researchers Locate Flaw In Bitcoin Protocol
An anonymous reader writes "Researchers at Microsoft Research and Cornell identified a potential flaw in Bitcoin's transaction propagation. In a recent paper they show how miner nodes in the Bitcoin network have an incentive not to relay transactions to the rest of the network, and propose to implement a scheme that rewards nodes [PDF] for relaying messages."
They seem to do lot of cool stuff. From that Courier tablet to studying Bitcoin. Even while Microsoft doesn't realize their R&D section has a great amount of potential, it's actually the only major company in the industry that does have such research center. I wish I worked there :-P
It still sounds like a better system than our current financial institutions.
"If any question why we died, Tell them because our fathers lied."
Well, IBM do have a fairly large research division too.
You're the guy that said he worked in marketing yesterday. Why is it that all UIDs over 2,000,000 seem to do marketing for MS?
which is totally what she said
Only a small fraction of bitcoin nodes (e.g. 1%) are mining nodes, and they all relay transactions as relaying transactions is very cheap to do. The problem they're describing clearly does not exist. If it did someday turn out to be an issue you can address it by users handing their transactions directly to various miners, you don't need some crazy complicated reward scheme.
It's also not news— their contribution isn't insight on incentives but a complicated sibyl resistant reward scheme for trees (which the bitcoin network is not) which requires doubling the cost of forwarding a transaction every two hops it takes. (By making every node perform a great many additional cryptographic signatures and checks in order to track the reward)
If a LARGE proportion of bitcoin nodes are run by assholes who refuse to distribute transactions then the network may fall apart.
This system seems to add a lot of complexity to solve something that has not proven a problem.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
This doesn't really make sense. Clients forward transactions as well as miners (and typical clients are connected to 8 other clients, making it a very well connected network).
Granted, there is no incentive to forward transactions, but if nobody forwards transactions then the network won't work so ultimately it's in the self interest of all users to do so. Some miners may decide not to do so, in the hope that they will be the one who solves the block and get the transaction fee. But they are not actually gaining anything by doing so. They are making other miners potentially miss out on transaction fees but it doesn't improve their chances of winning the block and therefore getting the fee and there is no way they can know what transactions other miners have picked up through other routes via the network.
I think the conclusion is wrong; while there is no incentive to forward the transaction (beyond stability of the network), there is also no obvious disincentive to do so as the cost is tiny (the cost of the bandwidth to forward it)
A bug can exist without it immediately causing problems. It's generally best to fix things before they become a problem, not afterwards.
vos nescitis quicquam, nec cogitatis quia expedit nobis ut unus moriatur homo pro populo et non tota gens pereat.
when you wrote "denial" did you mean "in a discussion involving several dozen people, one participant denied the existence of the problem while everyone else discussed whether the flaw is a practical problem or how it could be solved"?
Understandable typo, the keys are right next to each other.
Not to mention "engaging in a constructive discussion with one of the original authors of the paper, who hopped in and thanked people for their interesting comments".
Mod parent up.
Donate free food here
But seriously, their R&D department do some pretty cool stuff. Even though MS manage to churn out nine-nines of crap products, occasionally they still come out with something awesome that they manage to get to market (think Kinect).
The problem with that idea is that Kinect was a 90%+ finished product when they bought it. They polished it for use with the 360, it always takes them some time to fuck up a new technology sufficiently for their branding, and kicked it out the door. And it's taking them how long to kick out a PC version even though hobbyists have been doing it all along? Microsoft is pathetic at everything but illegally exploiting their opportunities and believing otherwise is ignorant at best.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The value of a good is actually whatever a third party is willing to give you in exchange for that good... This value is completely arbitrary, and allows products with no physical value (eg software) to be sold for huge amounts of money or other goods...
Similarly, money itself has no real value, only the value that others are willing to give in exchange for it.
The advantage of bitcoin, is that while its effectively a worthless token system, just like regular cash, it is a finite supply and thus not subject to the whims of a central authority.
Personally i use bitcoin a lot, primarily as an intermediary currency because i can buy bitcoins with money i hold in one currency, and then draw it out again in my local currency without incurring fees levied by existing currency exchange establishments.
http://spamdecoy.net - free throwaway anonymous email - avoid spam!
If people stop mining bitcoins now, the people at the top will stop winning, so of course they are going to deny. You know, kind of like global warming
A bad analogy is like a leaky screwdriver and that analogy has covered the floor in so much water that it is like a really tricky crossword puzzle.
SJW n. One who posts facts.
I got bored of the Wii gimmick and PS Move pretty quick. So I didn't even bother buying Kinect for my 360. How is it any better?
It's not. All three non-haptic (don't give me that "vibration is feedback" claptrap!) motion gaming controllers are absolutely horrible to use.
However, the Kinect is an amazing machine vision system. SLAM, 3d scanning, etc, all for something the size of a Toblerone you can buy off-the-shelf for cheap.
And Sony haven't done that? Oh wait they did.
This;
The stability of the current desktop computer market is so important to Microsoft that they will practically never actually innovate. They have an R&D department for two reasons. 1) To keep the ideas away from other companies by patenting them and then not licensing them onward 2) To keep the good people away from other companies by using them to create patents.
The reason not to work for Microsoft R&D is that, whilst you will be comfortable, well fed and well off, you will lead an empty life and they will suck your soul out of you.
=~ s,(.*),<sarcasm>$1</sarcasm>,g if any_point_you_wish();
Google as well. Saw an interesting article on Google X labs, their "skunkworks"-style division yesterday.
http://www.slashgear.com/google-x-labs-plans-robot-researchers-to-map-the-future-14194990/
There's a link to the poorly-paywalled nytimes article in there. Funny thing is they like to keep the fact that they're doing research a secret and constantly emphasize that they put very little money into research, because research makes shareholders nervous. Shows you how far ahead shareholders (or their HFT servers) are thinking.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Problem is, the final 10% polishing is actually pretty damn hard. If you've done software development, getting to the point where the basic features work is really quick. But getting to the point where it's releasable and usable takes a lot of effort.
It's one thing that Apple is known for (most innovations that are "cool" are at the 90% stage, but it still takes a ton of effort to get it to the stage where people other than geeks and engineers can USE it).
For Kinect, the final 10% would involve packaging (how does Kinect look, and will it fit with the rest of the equipment?), fitting the stuff inside the package (does it fit? Does the enclosure need redesign?), and more importantly, manufacturability.
Sticking a reference design in a box is not easy. A lot of work is required in order to be able to build in huge volumes - are the parts available in quantity (and cheaply)? Can it be assembled easily or are there fiddly calibration bits that'll take time to work? Are there simple pass/fail criterion?
It takes a lot of work. For open-source, you can abandon it after the 90% point (and most stuff is - the final work is the boring dull stuff no one wants to do), but it's not going to fly for commercial products that you want people to buy. And they know when a product was skimped on.
Heck, even the UI of a product is important, and Kinect took some beating there.
(It's why you get reviews on "solidness" - a minor detail but relates to build quality, ditto with use of "cheap plastic" or worse yet, "cheap feeling plastic".) It's that final 10% that Apple is well reknown for, and if it was easy, well, Apple would be dead and there would be tons of products with well designed UIs and very nice casings and such.
Bell Labs also used to set the standard in R&D,