Bitcoin Gold hit by 51% attacks, $72K in cryptocurrency double-spent

https://thenextweb.com/hardfork/2020/01/27/bitcoin-gold-51-percent-attack-blockchain-reorg-cryptocurrency-binance-exchange/

by scalableUnicon • 6 years ago

342 187 6 years ago

thenextweb.com

pwinnski• 6 years ago

This is good for Bitcoin. /s

tgsovlerkhgsel2• 6 years ago

Surprisingly, all cryptos (including BTG) seem to be going up. Normally a 51% attack on any somewhat-known cryptocurrency pushes the price down.

This kinda confirms that BTG being not just susceptible to 51% attacks but also getting hit by them isn't a surprise to anyone.

Edit to add: For anyone not familiar with the space, Bitcoin Gold is one of the many forks of the main Bitcoin blockchain, and one of the least meaningful among the ones commonly known. Here's the map of the main forks: https://i.redd.it/1pvmr98w5x041.png -- the main chain is by far the most known/popular/valuable, followed by Cash and SV in this order, followed by Gold far behind the rest.

Useful metrics are value/market cap, number/size of exchanges supporting it, or hash power. Hash power roughly correlates with value.

A main-chain Bitcoin (BTC) is worth about $8750 and basically the reserve currency of the crypto world (roughly all exchanges will have it), Bitcoin Cash (BCH) about $370 and has 400+ markets (that's as much as Coinmarketcap will show), Bitcoin SV (BSV) about $300 and 154 markets, Bitcoin Gold about $12 and 74 markets. Too lazy to count unique exchanges (an exchange can have multiple markets per coin).

Edit: Exchange listing counts here https://news.ycombinator.com/item?id=22161472

chrisco255• 6 years ago

Because most cryptos are traded in terms of BTC or ETH, if either of those two go up, virtually all other coins tend to rise as well. I haven't seen altcoins decoupled since 2017.

derefr• 6 years ago

I feel like every attack on these networks that goes from theoretical to real (or that gets demonstrated on increasingly larger scales), will actually tend to cause the market to get more bullish on the ecosystem as a whole.

It’s a kind of de-risking—not in the sense that the particular blockchain, or blockchains in general, are now any less vulnerable to the attack (Sybil attacks generally are like the Halting Problem of open consensus systems—no real way around them) but rather that these attacks, for some investors, go from scary “unknown unknowns” to “known unknowns” that can be quantified in their impact, and thus ROI models can be clarified, making cryptocurrency’s value as an asset class more legible. Legible assets always have a place in a hybrid-strategy portfolio; while illegible assets (like illiquid real estate from the housing crash) almost never do.

basically the reserve currency of the crypto world (roughly all exchanges will have it)

I would say that that’s more like either Monero or USDC right now: these are the cryptocurrencies people ask for when they just want cash but want to let you pay them in crypto, because you can cash out of crypto entirely in a non-value-losing way pretty well from either (with Monero, because it has low TX fees and fast processing times, so you can get rid of it in seconds; with USDC, because it’s stable-ish for now, so you don’t need to worry on a scale of minutes whether it’ll keep its value.)

Which is similar to what “reserve currency” means in practice for most people (other than banks): it’s the currency they’d prefer to be paid in, and the currency you’ll see them trading in their own currency for in the event that their own currency experiences high volatility.

lawlessone2• 6 years ago

Surprisingly, all cryptos (including BTG) seem to be going up

This might be because the "halvening" is this year.

Also all stocks are down due to the corona virus. which is allegedly a reason bitcoin is high.

fabianfabian• 6 years ago

Well it is, any copy cat coin sharing the same hashing algorithm as Bitcoin has this risk. So stay away from shitcoins.

Edit: I was wrong about BTG sharing the same algorithm.

brokensegue4• 6 years ago

I don't think Bitcoin gold uses the same hash function as Bitcoin

abstractbarista• 6 years ago

I think it's more complicated than that. You'd need enough computing resources to "beat" half of the Bitcoin network's current hashrate, which is absolutely massive compared to BTG's.

Oops: I see what you mean though. Because there's so many BTC miners, they can easily swap over to BTG to overwhelm the much smaller network.

Tepix• 6 years ago

Equihash is not SHA-256.

consp• 6 years ago

Every coin which uses the same proof of work method has this problem. It is independent of the actual hashing algorithm used.

This is also not the first time this coin has been targeted.

mywittyname• 6 years ago

This is sarcasm, but it really is: with crypto, there's strength in numbers.

piker• 6 years ago

Note this is "Bitcoin Gold", not Bitcoin.

Krasnol• 6 years ago

Funny how the whole article talks about Bitcoin Gold (BTG) but some automatic script liked Bitcoin (BTC) right in the first sentence. I wonder if anybody checks those articles after they've been posted or are those already automatically generated?

sp3322• 6 years ago

The linked-to affiliate doesn't support BTG https://bitcoinist.com/etoro-exchange-clarify-position-on-bi...

astrodust7• 6 years ago

This is just a warm-up for taking on Bitcoin.

redisman• 6 years ago

The scale would be orders of magnitude bigger.

gnulinux2• 6 years ago

I doubt any single party owns enough compute to perform 51% attack on Bitcoin. Not now, maybe in the future if bitcoin's popularity significantly dies, they can do that.

s_dev• 6 years ago

There isn't a state actor or company that overturn Bitcoin with computing power.

dajohnson89• 6 years ago

i wonder if this will cause a fork.

sp3322• 6 years ago

No, this won't cause a fork. To be specific, little forks happen all the time as different clients get information about new blocks at different times. So blockchains are very resilient to that kind of thing. Clients only continue from the longest legit chain they have seen, so whichever side of the fork has more hashpower on it will win in a way that's pretty transparent. So the attacker did cause a fork, so that they could spend coins once on each side, but all clients other than the attackers' would agree on which side was legitimate. So once the attack is over, it settles down immediately.

joosters• 6 years ago

It was a fork! That's how the double spends work. The attackers generated a new chain of blocks from just before their transaction, and produced their chain so fast that it became longer than the 'real' chain, causing miners to accept it as the legitimate record of all transactions.

As for 'resilient', try telling that to the people who were robbed of their coins because of this attack!

propter_hoc• 6 years ago

Second time this has happened to BTG. Boggles the mind that people continued to use this coin. https://fortune.com/2018/05/29/bitcoin-gold-hack/

aeyes• 6 years ago

Do other coins have any countermeasures against this? Other than it being expensive to control 51% of the networks hash rate?

I guess raising the amount of required confirmations helps but even then it's just a matter of time.

spir4• 6 years ago

Yes, Ethereum is transitioning to proof of stake.

Proof of stake is more secure than proof of work because an attacker must acquire a large amount of ETH each time they attempt an attack. Attacks against proof of stake are incredibly capital-inefficient.

WAHa_06x36• 6 years ago

The cost is the countermeasure, by design.

rocqua3• 6 years ago

The main trick is to use a hashing algorithm that differs enough from that used by bigger chains, so there is no easy way to redirect hashing power from somewhere else to your own chain.

hatinthecat3• 6 years ago

0chain does. It uses proof of stake and a block is only considered finalized when it is the sole ancestor in its generation.

galactus• 6 years ago

"use"

est31• 6 years ago

He then provided a screenshot showing that Binance had since increased their BTG withdrawal requirement to 20 confirmations.

The journalist has missed an important part of the github gist that their story bases on:

Based on Nicehash market price data for Zhash we estimate the cost of generating each reorg at around 0.2 BTC (~$1,700) and the attacker would have recouped around the same value in block rewards. Therefore, it is possible that the attacks were profitable if the double-spends succeeded at defrauding the attacker's counterparty, or break-even if the double-spends were unsuccessful. This suggests that a confirmation requirement on the order of tens of blocks for BTG is still far too few to make the budget constraint to launch an attack significant.

Misdicorl• 6 years ago

Double spends are an inefficient way to profit from an attack, they're merely the advertising/marketing angle.

The real profit will come from shorting the currency and capitalizing on the subsequent crash due to the crisis in confidence.

wmf2• 6 years ago

If you can short such an obscure coin and if there's a crash. Sometimes these attacks are already priced in.

gruez• 6 years ago

Note there are plenty of other cryptocurrencies that are susceptible.

https://www.crypto51.app/

dang3• 6 years ago

Current discussion at https://news.ycombinator.com/item?id=22160523

Also in 2018: https://news.ycombinator.com/item?id=17173051

drcode7• 6 years ago

ELI5:

Lots of cyptocurrencies use the same mining algorithm, i.e. they require the same type of puzzle to be solved to make money creating blocks. In recent years, lots of online services have sprung up to offer cloud mining, which people usually use to mine blocks on the bigger cryptocurrencies, like Bitcoin Core or Bitcoin Cash.

However, since the smaller cryptocurrencies, like Bitcoin Gold, have less users/miners, they also require easier "puzzles" to be solved, which opens an opportunity for any random person to pay some $$$ to hire a bunch of these cloud servers for a limited time and point them at these easier puzzles, which can cause such a smaller blockchain to get confused about account balances. The attacker can then re-spend the same currency multiple times to make a profit.

AFAIK there aren't really any good solutions to prevent this problem- For complex game-theoretic reasons, simply changing the mining algorithm to something different doesn't really offer much protection. (Some folks believe if these smaller currencies were to move to "proof of stake" it could help solve this problem, but this is an extremely contentious topic.)

3pt141592• 6 years ago

And it isn't like this problem wasn't foreseen ahead of time. I repeatedly tried to convince people that it was a real issue back seven or so years ago only to be met with (apparent[0]) scepticism that it's a real attack vector.

[0] Lots of millionaires came out of the cryptocurrency era. Sock puppets are cheap in comparison.

spir4• 6 years ago

cryptocurrency era

Cryptocurrencies and their associated boom-bust market cycles are here to stay.

95% of blockchain development happens on Ethereum, and Ethereum is growing well, https://medium.com/@jjmstark/the-year-in-ethereum-2019-24201..., so the idea that there was a cryptocurrency era that's ended is not true.

drcode7• 6 years ago

Thanks for helping me to buy lots of inexpensive cryptocurrency back in 2013, by keeping the prices low with your skepticism!

gfodor• 6 years ago

Given that the number of 51% attacks has been quite rare and relatively low impact so far, I'd argue that your skeptics are still winning the argument. Far more problems have come from security failures outside of the cryptocurrency itself or predatory practices.

antsoul• 6 years ago

I trust this guy : https://media.ccc.de/v/thms-26-cryptography-of-killing-proof...

And he's behind the crypto of GNU Taler and Polkadot

zionic• 6 years ago

IMO proof of stake is a lot less contentious than you imply. ETH2's slashing algo should make these types of attacks very hard.

For the curious a simple breakdown Ethereum 2.0's Proof of Stake (PoS) plan is:

-Minimum 32 ETH to stake

-Staking locks the currency in the staking pool

-Your node votes on the validity of the transactions (this is super light weight and fast, can run on a rPi instead of huge mining nodes).

-If the network agrees you was acting maliciously your locked stake begins to be slashed/burnt.

-Voting with the majority gives you a % of the block reward.

This means a 51% attack on the chain requires 51% of the currency staked which would be extremely hard to get without skyrocking the price (making 51% exponentially harder to achieve). They've also done some spooky proofs I don't understand that make the actual number to take over the network >51% (70% or so IIRC).

So it's green, fast, and harder to attack successfully. And unlike PoW, if you fail your "attack money" gets nuked.

StavrosK2• 6 years ago

And unlike PoW, if you fail your "attack money" gets nuked.

To be fair, in PoW your "attack energy" (and thus money) gets nuked too.

drcode7• 6 years ago

I'm a full believer in POS, but if you don't think that asking Bitcoin variants to switch their algos to POS is contentious...I don't know what to tell you.

WorldMaker2• 6 years ago

Some of the contention is directly in your choice of words: "should" and "plan". So far no Proof of Stake system has made it into the wild. There's a lot of talk about Proof of Stake, a lot of planning, a number of "almost attempts", but still no one running it at a big scale. It's trapped in "Soon™" the way Ethereum has talked about it, for years now. That's certainly an easy form of contention when even the biggest group talking about Proof of Stake have remained slow to pull the trigger.

im3w1l• 6 years ago

Is it possible to spread conflicting information get half people voting one way and half the other for the sole purpose of griefing their stakes?

andrewla3• 6 years ago

The lack of action around ETH2's move to PoS makes me somewhat skeptical of the confidence in these arrangements.

Does each block need a strict majority of outstanding currency to pass muster? It seems like it would be super risky to align yourself with any stake unless you were sure that it was going to be the majority, lest you inadvertently follow a post-facto "malicious" branch.

Therefore it seems like it might require less than 51% of outstanding currency, depending on the level of risk you're willing to take on, and how much active stake is willing to commit itself to proving maliciousness -- if you're leading the "that was malicious" faction but your faction fails to assemble more stake than the attacker did, then instead you get burned, so there's no guarantee that evildoers will be brought to justice; and aligning with a reorganization in ETH is dicier in many ways (because of the per-address nonce's) than it is in a UTXO coin.

Attack vectors are never within the bounds of tidy proofs of complex ideas; Bitcoin's brute-force solution is very simple to verify the correctness of, and the effective cost of pulling off a double spend is fairly easy to compute from first principles with some very weak assumptions about the quality of the hash function used.

I'll give more credit to proof of stake when Ethereum makes the transition; at least then there's some skin in the game.

nullc7• 6 years ago

"slashing" does nothing to address the fundamental problem. It leaves you with the same circular dependency.

Step 1. Acquire crypto currency. Step 2. Stake. Step 3. unstake and sell cryptocurrency. Step 4. use older keys to produce an alternative history.

Or, to simplify things, let other people do 1/2/3. Then purchase or hack their now-worthless old used keys to use in your attack... keys which they have no reason to protect and/or not sell. At most, all slashing does is makes Step 3 take more time.

I say "at most" because it doesn't necessarily do that much: if the funds you can earn from the attack (from double-spends and/or shorts) are large compared to the staked amounts, then step 3 isn't even required.

POS is fundamentally circular: you use ownership to determine ownership.

The only solution to this is to introduce another consensus mechanism like POW or, more commonly in POS proposals, a centralized authority. Some just assume the users are communicating over a synchronous lossless global totally ordered reliable broadcast-- which, again, is equivalent to running on top of another consensus system.

There is a reason you see people promoting POS that have an established history of committing fraud: the idea is most convincing if you obfscuate the details so much that no one is going to be willing to waste their time reviewing it. This is one of the classic moves used to convince someone to agree to a fradulent deal-- baffle 'em with bullshit.

admax88q• 6 years ago

The biggest flaw in Proof of Stake IMO is that it then costs you nothing to fork.

Forking bitcoin requires deciding which fork to spend your mining processing time on. Forking a PoS coin does not, since you can use the same coins for stake on as many different chains as you want.

MadWombat3• 6 years ago

How does this deal with very large transactions? If someone wants to pay someone a billion ETH, where do you find enough stake-holders with big enough stakes?

hatinthecat3• 6 years ago

You should also take a look at 0chain. They are using proof of stake and have decentralized storage.

spir4• 6 years ago

AFAIK there aren't really any good solutions to prevent this problem

https://blog.coinbase.com/how-coinbase-views-proof-of-work-s...

Coins at the greatest risk of 51% attack are the ones where there exists large amounts of hashpower not actively mining the coin that could begin mining and disrupt the coin’s blockchain.

Also, Ethereum's upcoming transition to Proof of Stake is not contentious, it's a large-scale project years in the planning and execution.

drcode7• 6 years ago

If you disagree, please post a proposed solution, instead of sharing a quote that describes the existing problem.

snarf212• 6 years ago

I don't think this is even a problem. Most of these so-called "sh!tcoins" have no business existing at all. This just shows how risky they are to hold and people should move on.

I know people love proof of stake as a "solution" but you give up decentralization for "security". If that is what you want, use a bank.

Erlich_Bachman• 6 years ago

This is really the best way of looking at it. We are discussing these problems and how to solve them, but they aren't even problems of cryptocurrencies in general, they are only problems of these shitty forks that have added nothing to the field, that exist only because use managed to bamboozle a small number of poorly educated users into thinking that they offer some real value...

robcohen• 6 years ago

Most of the coins do not have merit, but there are PoS coins that are legit. PoS will likely result in more decentralization, not less. Cardano is aiming for 1000 stakepools, which is far more than the 5 or so pools that exist in bitcoin right now.

root_axis• 6 years ago

They have just as much intrinsic merit as bitcoin, just less popular.

witweb• 6 years ago

There is no Bitcoin Core! There is only one Bitcoin using Bitcoin Core as one of its clients used to connect to the Bitcoin blockchain. The rest are just irrelevant forks.

paulmd• 6 years ago

Proof of work only reaches Nakamoto consensus if the average value transacted per block is less than twice the amount paid to miners. Otherwise it potentially becomes viable to 51% attack - it becomes cheaper to buy miner time to reverse my purchase of internet heroin than to buy the heroin.

Thus, there is a limit to the amount of economic activity that can be "safely" transacted by a proof of work chain per unit time, based on the amount of inflation/fees of that particular network. The more fees and inflation, the higher the economic value that can be transacted safely.

The actual real-world limit will be somewhat less than 2x because of options trading and other off-blockchain transactions.

Yes, this poses problems for smaller currencies where the average amount transacted per block is quite small. Bitcoin has not just a "network effect" of adoption resulting in places to spend it, but also a network security effect, where the vast amount of spending makes it much more economically difficult to justify a 51% attack.

(That or you need to wait increasingly long periods on these shitcoin chains before accepting them as "final" and transferring goods. Eventually all chains should reach consensus, as long as you wait long enough that it would be economically unviable to

And note that this is actually a parameter that cryptocurrencies can set themselves. When (eg) Ethereum cuts the block rewards, that results in network hashpower going down, and thus reduces the economic throughput that is possible before nakamoto consensus falls apart. Same for Bitcoin's block halvening.

qes• 6 years ago

AFAIK there aren't really any good solutions to prevent this problem- For complex game-theoretic reasons, simply changing the mining algorithm to something different doesn't really offer much protection. (Some folks believe if these smaller currencies were to move to "proof of stake" it could help solve this problem, but this is an extremely contentious topic.)

Decred's mixed PoW/PoS would be extremely expensive to 51% attack, and would require a large amount of funds to be locked up in voting tickets for random amounts of time ranging from a few days to several months - so if you successfully attacked it, you'd presumably reduce the value of Decred and the many millions of dollars worth of Decred you had frozen in tickets.

Priem193• 6 years ago

You meant Bitcoin; Bitcoin Core is the name of the software to run a Bitcoin node.

knocte4• 6 years ago

I wonder why this ended up in the front page of HackerNews? It's not news that altcoins are much much easier to attack than the top coin(s). Lesson to learn here: top coins are not only better due to the network effects (users and developers), they are also better in terms of security (it's much more expensive to carry out an attack in BTC or ETH, for example).

xyst• 6 years ago

Would it be fair to say altcoins are the “penny stocks” of the cryptocurrency world? Easily subjected to price manipulation and typically the perpetrator doesn’t have to spend too much.

knocte4• 6 years ago

I think altcoins are not even penny stocks, they will die soon in the same way there are no other networks these days that try to be the internet. The penny stocks are the Ethereum tokens.

rudolph9• 6 years ago

When I first read it, I read "Bitcoin Cash" which stuck me as alarming as it's one of the larger ones. But upon further investigation realized that it's "Bitcoin Gold" something I have no recollection of.

knocte4• 6 years ago

I don't consider Bitcoin Crash as one of the larger ones (it possibly has less than 5% of BTC's hashpower).

duxup• 6 years ago

As far as showing up on the front page goes the HN community has shown to have a lot of interest in the strange world of cryptocurrency. I'm not surprised it made it this far.

avip• 6 years ago

Crypto failures were always well received here. The infamous DAO drainage alone triggered multiple 200+ comments threads.

bdcravens7• 6 years ago

It's not news that altcoins are much much easier to attack than the top coin(s)

Not everyone here is a cryptocurrency enthusiast. The fact that this is even possible is interesting by itself; an instance of it happening even more so. What's not news to you is indeed interesting to someone else. Alas, this isn't Reddit, so the usual "OMG Don't spread FUD!" response doesn't apply here.

hatinthecat3• 6 years ago

You’re assuming all blockchains are created equal. A new smaller blockchain can pop up and provide better security, finality, and the coin could actually be backed by something.

knocte4• 6 years ago

hahaha!

milansuk2• 6 years ago

The block which includes double-spent is invalid. When an honest node chooses the "strongest" chain it should check block If it's valid, not just look at a number of confirmations.

This is also true for blockchain browsers(and their api), which apps use to confirm the transaction(most of users don't run full node). The only way how 51% attack can be successful in the long term is that honest nodes(and blockchain browsers api) are re-configure to ignore double-spent(at least for a particular time period).

wcoenen• 6 years ago

How do you know which side of a blockchain fork is the double spent, and which is the original?

milansuk2• 6 years ago

This is a valid point. Sorry for my post. Blockchain has few moving parts, but the whole game theory around it is very complex.

creato• 6 years ago

Someone will be left holding the bag. Your post assumes it will be the double spender, there is no reason to assume that.

m3kw9• 6 years ago

Looks like they took a loss doing that attCk

bdcravens7• 6 years ago

There are a lot of Bitcoin advocates that would attack out of motivations other than (short-term) profit.

bobmaxup• 6 years ago

https://en.wikipedia.org/wiki/Sybil_attack

maitredusoi• 6 years ago

who on earth has got Bitcoin Gold in his pocket ??? ;)

tgsovlerkhgsel2• 6 years ago

Since the other post got buried in a subthread: This is about Bitcoin Gold, not Bitcoin itself.

Bitcoin Gold is the least relevant of the forks (worth ~$12 per coin while the main chain BTC is worth ~8750 and the two major forks BCH/BSV are worth around 300, and only 7 of the 20 largest exchanges (by liquidity, according to coinmarketcap) list it - even though most of them list plenty of altcoins/shitcoins. For comparison, Bitcoin Cash is listed on all of them, Bitcoin SV on 14 of them. Additional stats here: https://news.ycombinator.com/item?id=22160458

brokensegue4• 6 years ago

clearly you've never heard of Bitcoin Diamond

Relys• 6 years ago

I prefer Bitcoin Platinum.

DonHopkins• 6 years ago

The densest by far is Bitcoin Black Hole: hype goes in, but never comes out.

bdcravens7• 6 years ago

Meta: I spend a lot of time in crypto(currency) subreddits, and of course approach those conversations differently than I do when I see the same topics pop up on HN. That said, I see a lot of the Reddit-style comments and terminology ("altcoins", "shitcoins", derisive names, etc) show up where when there's a crypto discussion. Does this happen in other subjects and I'm just unaware of those topic's subcultures? Or am I correct that the level of discourse for crypto is that much lower?

aprao2• 6 years ago

I wouldn't necessarily call the discussion "lower" but you can see similar colorful language in forums dedicated to trading equities/options.

bdcravens7• 6 years ago

I imagine so. I think my question (maybe I missed the mark) was is that does as much as that leak into HN (where I consider the level of discourse far higher than the Internet as a whole) as much for other topics?

drcode7• 6 years ago

As someone who's been part of the crypto community since 2011, the level of discourse in most of cryptoland is rock bottom. I attribute it to the decentralized nature of the technology, which encourages lots of people to attempt manipulate prices through trolling.

bdcravens7• 6 years ago

I would concur (I've been around it a similar amount of time, building my first GPU rigs around that time). I would say it was once a bit better, but maybe that's just rose-tinted nostalgia. ("the good ole days")

dang3• 6 years ago

A current thread about 51% attacks is here: https://news.ycombinator.com/item?id=22160523

jackalo• 6 years ago

That is a thread about the cost for a 51% attack against various crypto currencies, not about Bitcoin Gold actually being hit.

dang3• 6 years ago

Yes, that's why we didn't merge the two threads.

TazeTSchnitzel• 6 years ago

Binance had since increased their BTG withdrawal requirement to 20 confirmations.

Perhaps they should require some multiple of (amount of the transfer / cost of the hashpower needed to mine one block)?

s_gourichon• 6 years ago

BTG might collapse as a result.

This might help general awareness that minor coins without a differentiating technology are simply highly vulnerable uninteresting clones, not worth any attention and thus, value. Perhaps some would just disappear, in a spiral of lower value, lower hash rate, more vulnerability, till all miners leave towards other, stronger coins?

This might sanitize the whole cryptocurrency domain a little.

Or not?

kybernetikos• 6 years ago

It's been known for some time that anything out of the top 10 that uses a pow algorithm for which you can buy hashpower in the market is pretty easy to run a doublespend on. It doesn't seem to have had a huge effect on adoption of those coins though.

AdrianB12• 6 years ago

Just an observation: 51% attacks are happening there days in some countries in governments. When 51% gives you the absolute power in a bitcoin, it gives you enough to rule a country and push it to 100% (there are a few real life examples). Maybe 51% is a threshold too low for some things.

Synaesthesia• 6 years ago

That’s never really true, because even in a dictatorship the government doesn’t have total control of everything. And a 51% govt in a democratic country is constrained not only by rival political parties but also the business sector and public outrage.

AdrianB12• 6 years ago

Just 2 words: North Korea.

redis_mlc• 6 years ago

Oh. Again.

latchkey2• 6 years ago

One point nobody is hitting on is that the price of BTG pumped a few weeks ago for no apparent reason. I guess we know why now. Pump the price and then attack it for even more profit.

rootsudo• 6 years ago

The question now is: was hiring the cloud mining services cheaper than the reward of $72,000?

jb775• 6 years ago

1 for 1 so far on my 2020 decade predictions

https://news.ycombinator.com/item?id=21943830

Traster• 6 years ago

Sorry, but this doesn't seem related to quantum - I don't think you get credit yet.

H8crilA• 6 years ago

And all of that costed just about $1.2k, what a joke currency.

granaldo• 6 years ago

How disconnect the market is from facts. Price of Bitcoin Gold is not even affected by this news at all

https://www.coingecko.com/en/coins/bitcoin-gold

The market may not even understand what 51% is about

runeks• 6 years ago

Or maybe all buy orders have disappeared. Looking at the last exchange price does not measure the value of a cryptocurrency, you need to look inside order books to see if anyone is even interested in buying your cryptocurrency. It’s not relevant to the value of your cryptocurrency that someone was once willing to buy it.

Bitcoin Gold hit by 51% attacks, $72K in cryptocurrency double-spent

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