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Blockchain's Once-Feared 51% Attack Is Now Becoming Regular (telegra.ph)

Monacoin, bitcoin gold, zencash, verge and now, litecoin cash. At least five cryptocurrencies have recently been hit with an attack that used to be more theoretical than actual, all in the last month. From a report: In each case, attackers have been able to amass enough computing power to compromise these smaller networks, rearrange their transactions and abscond with millions of dollars in an effort that's perhaps the crypto equivalent of a bank heist. More surprising, though, may be that so-called 51% attacks are a well-known and dangerous cryptocurrency attack vector. While there have been some instances of such attacks working successfully in the past, they haven't exactly been all that common. They've been so rare, some technologists have gone as far as to argue miners on certain larger blockchains would never fall victim to one.

The age-old (in crypto time) argument? It's too costly and they wouldn't get all that much money out of it. But that doesn't seem to be the case anymore. NYU computer science researcher Joseph Bonneau released research last year featuring estimates of how much money it would cost to execute these attacks on top blockchains by simply renting power, rather than buying all the equipment. One conclusion he drew? These attacks were likely to increase. And, it turns out he was right. "Generally, the community thought this was a distant threat. I thought it was much less distant and have been trying to warn of the risk," he told CoinDesk, adding: "Even I didn't think it would start happening this soon."

4 of 168 comments (clear)

  1. We need to smash the money printing machines. by xack · · Score: 4, Insightful

    The entirety of the Netherlands is growing tulips instead of food. People are prostituting them selves for chucky cheese tokens entire coal power stations being built just for funbux.

    I hope the 51%ers wreck as many cryptocurrencies as possible to crash the market so the environment can be saved, graphics cards go back to making graphics and people go back to investing into stocks of real companies that provide real services.

  2. Bitcoin is the 10 cent deposit on the Coke bottle by goombah99 · · Score: 5, Insightful

    The goal of the 10 cent coke bottle deposit is NOT to make coke bottles into a hobo currency. The goal is to have distributed recycling (back when we reused bottles). To do that you needed an incentive.

    In a similar fashion, recycling (as opposed to re-use) in general was spawned as a PR move to solve a problem for the nascent alumumin can industry, and not because its somehow the ethical thing to do. Steel cans rust (or at least thy used to ) so they naturally biodegrade. Same with paper and cloth packaging. But rise of plastic in the 50s creates a non-biodegradable trash problem that people in the 60s really felt was a moral insult to mother earth. The aluminum can people saw the problem with introducing a product to replace steel cans that wasn't re-usable like glass and would not biodegrade like all other packaging and was even more resource intensive to manufacture. So they solved two problems at the same time: Promote recycling. By paying for aluminum cans they got people to see them as better for the earth. And they also got back their expensive materials to reprocess.

    So the point of paying for alumium was not to turn aluminum cans into Hobo currency either. It was to enable everything else. The fact that it induced the neccessary behaviours was the reason to pay pennies for cans.

    I perceive that people misunderstand the purpose of crytocurrency. The goal is not to have a currency. It's to have a distributed ledger but in order to have that a currency is neccessary for two reasonss.
    first, in order to vanquish the doule-spend problem it's essential to a crytpocurrency that it be very expensive to bless a ledger entry and because computing power grows the cost must increase with time.
    Second, since the whole point is that the block chain is a distributed ledger there has to be a way to pay the people who pick up the cans and bottles. Namely, you include a payment into the ledger too. So it has to be a currency.

    But the currency isn't the reason for it. it's the necessary glue to make it work

    SO the two problems with crytpo currencies that are intrinsic are not the currency part or the speculative bubble part. (afterall we could use cans and bottles as currncy if we really wanted to-- whether or not people accept something is a different matter than it's intrinsic value.)
    specifically: if the expansion rate of the cost isn't managed right it becomes an energy consuming nightmare. but if you undershoot the expansion rate then the double-spend problem isn't fixed.

    Getting that right is probably not yet solved by any existing crypto currency. But that doesn't mean it can't be gotten right. We just don't know either way right now.

    --
    Some drink at the fountain of knowledge. Others just gargle.
  3. Re:Bitcoin is the 10 cent deposit on the Coke bott by goombah99 · · Score: 1, Insightful

    indeed that is a question isn't it.
    It seems to me that if the expansion were done right then it should stay at exactly the same cost and only grow in proportion to the transaction's value. That is as computers make computation cheaper, raise the cost to the same constant cost. However, that doesn't solve the problem until the the cost is about 1/2 the transaction size.

    That being said the amount of energy spent on bitcoin is orders of magnitude less than the cost spent on Mastercard when you include all the costs. By all the costs I mean, mastercard is full of people (customer service... point of sale terminal installers, mail processing and mail delivery all are people neccessary to mastercard.) All those people have to eat and buy clothing. So there's a measurable slice of people needed for master card to exist. If you didnt need those people at all and could replace them all with "just" a low manpower nuclear power plant, the level of human labor freed up for other productive uses would be staggering.

    --
    Some drink at the fountain of knowledge. Others just gargle.
  4. Re:Bitcoin is the 10 cent deposit on the Coke bott by green1 · · Score: 3, Insightful

    But we know what value mastercard provides. We don't know what value blockchain provides.

    Comparing the power use of the two is therefore somewhat irrelevant.

    Mastercard allows me to shop both in person and online with certainty. I present my card, and within a couple of seconds we have certainty that my transaction is approved and will go through. I know that even if the merchant finds a way to double bill me, mastercard will indemnify me for it, and I know what the transaction will cost me in relation to the amount of money I have, and in relation to every other transaction I make, because they all use the same currency.

    Blockchain transactions on the other hand have none of the certainty, none of the speed, and none of the security. They also aren't tied to the currency used for everything else, so the wild price swings can, and will, affect you. Also by your own admission, blockchain isn't even supposed to be for payment, just as a distributed ledger. Something that nobody has ever found a use for that isn't already better served by other existing tools.

    I'm not saying the technology is completely useless. But I can confidently say that nobody has found a practical use for it yet other than to try to find the "greater fool" willing to pay more for it than it cost the original person.