With PoS could you take over all coins by buying 51% of the existing coins? So if the market cap of ETH is 200BB spend 100BB to double your money?
https://www.coindesk.com/crypto-51-attacks-etc
Furthermore it's become pretty clear from the many attacks on value tokens in Etherum & BSC DeFi that the attacker can move faster that the market and drain any liquidity pools/exchanges that have open offers into something that isn't going to collapse.
The theory early on was that the coin cratering b/c of an attack would be an extra deterrent, but the price of coins that have been successfully 51% attacked says otherwise.
Here's another cryptocurrency in the top 100 that has suffered many 51% attacks.
https://cointelegraph.com/news/bitcoin-gold-blockchain-hit-b...
Sometimes people argue that a nation state could "shut down" bitcoin for some amount of money -- say $10B. With that, they could buy enough mining equipment to publish empty blocks and throttle the ability to send transactions.
Part of my skepticism of this idea is that the bitcoin network is already so throttled but it does not seem to affect the value of the coin negatively. What would be hilarious would be if France decided to shut down Bitcoin, and succeeded, but the value of bitcoin then proceeded to increase 100x.
Etherum classic and Bitcoin gold come to mind. They are both in the top 100 still, and both have been 51% attack multiple times.
People who control stake can refuse to include (censor) transactions, as there is no market competition for transaction inclusion like in PoW. In PoW, if 51% of network power is censoring transactions, then censored transactions can attach a higher fee, which competing miners will use to buy more equipment and mine the censored transactions.
These are the ones I know about, that I learned in an evening of research.
It uses Verifiable Delay Function as an element of random number generation process. One can look into number of rounds of VDF and treat them just the way they treat proof of work today. It can be compared to determine which chain is the longer one.
No one would buy those from you, so at best you can burn money to burn other people's money at a premium.
My guess would be at some point people would realize a takeover was occurring and panic, but it seems like a 51% buyout would require an ungodly amount of money and time.
You can't really double-spend that way, but you can get a disproportionate amount of the shard rewards. In order to defend against this, other participants will also have to mine for a "more fair" alternate reality, so you end up getting a standstill where nobody can get economic advantage as long as the total power being devoted to preventing chain-shopping is greater than the amount spent on chain-shopping.
In the end the energy expenditure would likely be unchanged from the status quo, it would just be hidden behind a facade of inexpensive proof-of-stake validations that conceal the actual work being done to ensure that this is not abused. This way everyone can feel warm and fuzzy because there's no actual way to measure how much work is being done to keep the validation from being monopolized.
I don't think the network can figure out an "oops, AWS or Comcast went out; my nodes at home or in the cloud shouldn't get slashed" vs "lets sabotage an ISP or network for enough time to trigger penalties and repeat it".
These kinds of off-network incentives can disrupt the reward system. It's even possible to incentivize a lot of people to collude in a double spend attack if the rewards can be distributed to the participants.
Like suppose the banking system was running on ETH. Or if Colonial Pipelines used ETH.
1. They would drive the price up way past market price in an attempt to make such a large purchase. The cost of a large, rapid purchase is far, far from market price. Only a fraction of the market is willing to sell at current price.
2. If a country wanted to run on Ethereum, they could clone it, since they are giving up the benefits of a GLOBAL system when they take it over.
Lmk if you have any questions. Pretty interesting topic given the insane ETH valuation atm, in contrast to, say, Algorand. Network and first move effects, I guess.
In most double spent networks, people clamor for the coins so they can have the chance at double spending
In PoW networks that’s combined with renting/deploying hash power
In PoS networks its just taking over validators
Big ole party!
With PoW, it's all just physics, energy, and math. With PoS it's rich peoples opinions and validation. An attack on PoS will likely be political... and politics tend to slip into war if there's not enough adults in the room.