We sometimes hear about the danger of quantum technology defeating cryptography, although this is a false problem. On the other hand, I have never heard any thoughts about nuclear fusion energy that could disrupt the economy of miners. When this techno will be sufficiently mastered to be scalable in large quantities, it is possible, at least at the beginning, that a company or a state could obtain a large amount of the hashrate thanks to an abundant and cheap energy (the cheapest of the market)
Do you think this is a possible scenario or not?
I'm thinking about this in reaction to the book Softwar that I heard about which talks about the subject of a war between states to get the hashrate
Even with the abundant energy harnessed through fusion you would still need to manufacture the ASIC miners to obtain a significant hash rate. Also, if fusion energy becomes viable the most effective and long-term way of putting the energy to work may not be related to Bitcoin.
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Abundant energy is bound to have a major role in a field as competitive as mining. As far as ASICs are concerned, you're right but, still trying to look into the future, isn't there a time when a hypothetical technology could make mining much more efficient and create a centralization of the hashrate. That's kind of the idea
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I have thought of fusion-based mining before and piezo-based energy sources coming online and what it would mean for bitcoin...
The current supply (Coingecko) of BTC is 19.297M out of a possible 21 M.
The attack vectors would be use an abundant energy source to:
  1. Mine as much of the remaining BTC
  2. Control hashrate to block or censor specific transactions or applications built on top of Bitcoin.
  3. Control hashrate to burn / destroy things a la the novel "Dune"
If the aim is to destroy Bitcoin
1a) I see it as not a great strategy because at that point you're drawing attention to BTC and making it seem incredible valuable 1b) You're seen by the entire world as a financial terrorist in a way you can't even deny plausibly anymore
  1. Competing geopolitical adversaries both engage in it, thereby proving the thesis of adversarial money, plus waves hands difficulty adjustment (someone poke holes in this). Barring an adversary, see 3)
  2. Would have to destroy "last sane" snapshots everywhere all at once, no? Barring total destruction you still have possibilities of forks and network recovery
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Still more worried about specific aspects of elliptic curve cryptography being breakable / already broken, in secret.
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That make sense
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Energy and time are the primary inputs for all production, only limited by what materials you can acquire to use the energy to produce. So it's a good point - cheaper energy naturally means more mining, probably. But the game theory dynamics are pretty well proven in how things have played out since the inception of Bitcoin. It usually is almost as profitable to build to sell as build to mine, though specialisation in both is unlikely. So, while it would lower the cost of mining, and probably attract more miners, and enable more miner production, it doesn't change the Nash equilibrium that is also part of the "one shot principle" about money and digital scarcity.
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a company or a state could obtain a large amount of the hashrate thanks to an abundant and cheap energy
And then do what?
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Censoring transaction, or even mine from the previous block and take advantage of the double spending
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Mining a block that conflicts with an existing block but then becomes part of the chain with the "greatest work" is called a blockchain reorg. It is not a frequent occurrence, but bitcoin's design can handle that. And that attacker can only double spend their own transactions.
Censoring some (or all) transactions is definitely something a miner with 301 EH/s (of the total 601 EH/s .... which is the existing network's 300 EH/s plus the attacker's 301 EH/s) is certainly capable of doing. It's the finding and operating the 301 EH/s hashrate that I doubt even the most motivated nation state would be able (nonetheless willing) to pull off.
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