It's also not simply a matter of agreeing on what tasks to use. The task has to be computationally difficult to perform, but computationally trivial to verify. It must also be verifiable with only the context of the blockchain (no "oracle" that can make claims about real-world events).
Primecoin exist(ed?) and used the search for Mersenne prime numbers as its proof-of-work. That was 13 years ago and is still the only example I know of "proof-of-useful-work", and it would not be difficult to find sour voices challenging its usefulness.
While they don't have that many in the wild, the number of implementations it lists is still more than I expected. There's also the Monero 51% takeover, which was purportedly done using a PoUW technique to garner more hashing power.
The disappointing truth is that we simply don't know. Satoshi never explained it. For SHA-2 it can be used as a mitigation against length-extension attacks¹, and this seems like the most likely explanation, but it's just speculation.
It's a common misunderstanding that mining just gets harder and harder as time goes by and more coins are minted. It's often misreported that way. But in fact, the difficulty is dynamic and adjusts itself to keep minting at the predetermined rate regardless of the number of participants. Mining has gotten harder on long timelines, but only because more computing power has been added.
> Miners who successfully create a new block with a valid nonce can collect transaction fees from the included transactions and a fixed reward in bitcoins. To claim this reward, a special transaction called a coinbase is included in the block, with the miner as the payee. All bitcoins in existence have been created through this type of transaction. This reward is halved every 210,000 blocks until ₿21 million have been issued in total, which is expected to occur around the year 2140. Afterward, miners will only earn from transaction fees.
Difficulty and block rewards are separate things. There is no contradiction here.
Block reward stays constant, amount of work required (on average) to get a block reward is dynamic in order to make it so that total number of rewards given out over a length of time stays roughly constant.
So if too many block rewards are claimed in a given time frame, difficulty is increased to slow things down. If not enough are claimed then difficulty decreases to make it easier to get one.
I honestly don't know which part of "the difficulty being dynamic" is this hard to understand.
> The power needed to get a given amount of money doubles whenever the reward is halved.
Yes, by that moment it does.
And some miners still stop mining if mining became too unprofitable.
And the difficulty will decrease because less miners are mining.
And the power needed to get a given amount of bitcoin will decrease. (Not necessarily to the level before halving, ofc)
Or your comment was about this part of the grandparent comment:
> keep minting at the predetermined rate
?
If so, I think you misunderstood what they were trying to say (or their wording was misleading). It's a predetermined rate. Not a constant rate. It's predetermined to be halved at (roughly) certain moments. Halving happens about every four years, and pouring more power into mining won't make it happen significantly sooner or later. That's what they were trying to say.
Backed stablecoins aren't some anarchistic anti-government thing; they are highly regulated and will lose access to their banking if they don't follow the rules – rules which require them to freeze coins in cases of crime.
If you want to show a middle finger to government there are cryptocurrencies for that, but USD stablecoins with centralized backing is not it.
Back when Raspberry Pi 4 came out in 2019, the 4GB variant cost $55. Fast forward seven years and the same hardware with slightly less memory costs $83.75.
There was a time when computers just got faster and better so fast that you could barely get one set up at home before it was obsolete.
Just watching it now (and what a house it is). There's a TV in almost every room, and Fox News is on each of them. He says: "Yes, it is the same station on every television, because that's how the system is designed. It's designed so it'll play the same station all over the house. It happens to be Fox News, but I do flip around. It's not nailed on Fox News, in case you're wondering."
The Purism ones. They work mostly fine - outdated hardware sure, but it is all fast enough and works and is very usable as workstation of course depending on what you do. I do some rust, go, node dev and it works very well when plugged into a larger screen.
Primecoin exist(ed?) and used the search for Mersenne prime numbers as its proof-of-work. That was 13 years ago and is still the only example I know of "proof-of-useful-work", and it would not be difficult to find sour voices challenging its usefulness.