Quote from: gmaxwell on June 13, 2023, 07:52:41 AM

If that we're true you'd have a point, but the good news is that isn't.

It's possible using cryptography to construct proof for statements like "0xDEADBEEF is the hash of the tip of a blockchain starting at the genesis block where all rules pass, with total difficulty Y", where the proof is much smaller than the blockchain (in some cases only a few hundred bytes).

Such systems are already in production use for small programs today. Scaling them up to work over the whole bitcoin blockchain is a (considerable) engineering exercise, but I think it's inevitable-- well inevitable that the proof systems are developed to that extent. If Bitcoin will deploy them or not will depend on if anyone is still willing to work on it.

(And you should hope these tools are developed, because we've already seen what people do when validating the history becomes too expensive-- they skip it)

i'm skeptical that such a system could work for bitcoin unless they changed up the structure of bitcoin blocks to include some type of utxo set commitment inside each block. but i guess if you did that, maybe it could work.

because the way it is right now, an individual block doesn't really tell you anything about what the existing utxo set is or any of its properties. that would need to change somehow. Shocked