4 ms·

I haven't read the article, but I believe it will say something like, the continual investment is necessary in order for the transactions to be irreversible (se

I haven't read the article, but I believe it will say something like, the continual investment is necessary in order for the transactions to be irreversible (settlement assurance). I'm sure there are some forgotten altcoins out there still chugging along, but it probably does not take much money to hire sufficient hash power to double-spend those alts, or even re-write their history. For as long as bitcoin miners fight, tooth and nail, to hash incrementally more efficiently than their competitors, it will be prohibitively expensive for most actors to reverse transactions.

trixie_ 6y ago
Not saying this isn't a possibility, but you'd think in the last 5 years of thousands of altcoins this sort of thing must of happened at least once? I guess the interest has to be there to attack it? Though if the interest was there more people would be mining it. Something like that.
- brian_cloutier 6y ago
  It... has happened. Multiple times. Bitcoin Gold: https://cointelegraph.com/news/bitcoin-gold-blockchain-hit-by-51-attack-leading-to-70k-double-spend https://cointelegraph.com/news/bitcoin-gold-blockchain-hit-b... Vertcoin: https://www.coindesk.com/the-vertcoin-cryptocurrency-just-got-51-attacked-again https://www.coindesk.com/the-vertcoin-cryptocurrency-just-go... Ethereum Classic: https://cointelegraph.com/news/ethereum-classic-51-attack-the-reality-of-proof-of-work https://cointelegraph.com/news/ethereum-classic-51-attack-th... Google is happy to show you more.
  - trixie_ 6y ago
    Right, I guess I feel less at risk of being the victim of a double spend and more at risk with rewriting history. Are there any reports of that? Like coins I've held on the chain for some time being stolen?
    - hn_acc_2 6y ago
      The value of your long-held coins will be almost nothing if the network is vulnerable to double spend. The potential losses are huge (especially for exchanges etc.) from double spend attacks, and the value of a cryptocurrency is very much dependent on users' confidence in its resistance to attacks.
      - trixie_ 6y ago
        Good. My long held worthless altcoins will remain worthless and mine regardless.
      - wmf 6y ago
        Weirdly, this doesn't seem to be the case. Coins with no hashrate like BCH are still trading at pretty high prices. https://cointelegraph.com/news/bitcoin-cash-could-face-51-attack-for-10-000-in-rented-hashpower https://cointelegraph.com/news/bitcoin-cash-could-face-51-at...
        hn_acc_2 6y ago
        You're correct, and the market is always right after all. However I am confident based on previous events that BCH prices will trend strongly downward when news of the next successful 51% attack is released.
        gridlockd 6y ago
        BCH does have a significant amount of hashrate. A 51% attack being possible is one thing, it being profitable is another. If it's not profitable, it is unlikely to happen. If Hashrate was to drop significantly without commensurate price drops, attacks will happen and then the price will drop to compensate.
    - gridlockd 6y ago
      If you're just holding coins you're "safe" in the sense that you will get to keep your account balance. However, if the network is unstable, then that balance will lose value in real terms or even become worthless.
  - Drakar1903 6y ago
    I keep wondering what pushes people to stay in the ecosystem of the forked chain that quote unquote lost the fight.
- hn_acc_2 6y ago
  Bitcoin Gold was hit by double spend multiple times, and that's just what I remember off the top of my head. However there are obviously diminishing returns for such an attack. The alt coin value drops drastically when users find out about the attack and flee to more secure currencies.

trixie_ 6y ago

Not saying this isn't a possibility, but you'd think in the last 5 years of thousands of altcoins this sort of thing must of happened at least once? I guess the interest has to be there to attack it? Though if the interest was there more people would be mining it. Something like that.

brian_cloutier 6y ago
It... has happened. Multiple times. Bitcoin Gold: https://cointelegraph.com/news/bitcoin-gold-blockchain-hit-by-51-attack-leading-to-70k-double-spend https://cointelegraph.com/news/bitcoin-gold-blockchain-hit-b... Vertcoin: https://www.coindesk.com/the-vertcoin-cryptocurrency-just-got-51-attacked-again https://www.coindesk.com/the-vertcoin-cryptocurrency-just-go... Ethereum Classic: https://cointelegraph.com/news/ethereum-classic-51-attack-the-reality-of-proof-of-work https://cointelegraph.com/news/ethereum-classic-51-attack-th... Google is happy to show you more.
- trixie_ 6y ago
  Right, I guess I feel less at risk of being the victim of a double spend and more at risk with rewriting history. Are there any reports of that? Like coins I've held on the chain for some time being stolen?
  - hn_acc_2 6y ago
    The value of your long-held coins will be almost nothing if the network is vulnerable to double spend. The potential losses are huge (especially for exchanges etc.) from double spend attacks, and the value of a cryptocurrency is very much dependent on users' confidence in its resistance to attacks.
    - trixie_ 6y ago
      Good. My long held worthless altcoins will remain worthless and mine regardless.
    - wmf 6y ago
      Weirdly, this doesn't seem to be the case. Coins with no hashrate like BCH are still trading at pretty high prices. https://cointelegraph.com/news/bitcoin-cash-could-face-51-attack-for-10-000-in-rented-hashpower https://cointelegraph.com/news/bitcoin-cash-could-face-51-at...
      - hn_acc_2 6y ago
        You're correct, and the market is always right after all. However I am confident based on previous events that BCH prices will trend strongly downward when news of the next successful 51% attack is released.
      - gridlockd 6y ago
        BCH does have a significant amount of hashrate. A 51% attack being possible is one thing, it being profitable is another. If it's not profitable, it is unlikely to happen. If Hashrate was to drop significantly without commensurate price drops, attacks will happen and then the price will drop to compensate.
  - gridlockd 6y ago
    If you're just holding coins you're "safe" in the sense that you will get to keep your account balance. However, if the network is unstable, then that balance will lose value in real terms or even become worthless.
- Drakar1903 6y ago
  I keep wondering what pushes people to stay in the ecosystem of the forked chain that quote unquote lost the fight.
hn_acc_2 6y ago
Bitcoin Gold was hit by double spend multiple times, and that's just what I remember off the top of my head. However there are obviously diminishing returns for such an attack. The alt coin value drops drastically when users find out about the attack and flee to more secure currencies.