Sync – Can I sync a new node without connecting to a single dirty node?

There are some proof-of-work chains where pruning at nodes is the default. That is, the network does not depend on full nodes being unpruned at all.

Due to the pruning mechanism, Kaspa nodes only need to store up to 3 days of previous history in each decentralized system.

One. Does Kaspa rely on additional assumptions that Bitcoin doesn’t rely on for such pruning to work?

2. How does a Kaspa node construct its utxo set in this situation?

Who verifies signatures?

Let’s imagine that in the future, for some reason (either due to high storage costs or protests against on-chain inscriptions), all nodes on the Bitcoin network are pruned nodes. In that situation and within the current Bitcoin protocol:

three. Can I start a new node from scratch? Is it possible to check the last 550 MB of blocks without connecting to one full archive node?

4. Is it possible, using nodes that have just been started from scratch, to construct a set of UTXOs with some utxos created below the block height of the cut point by those nodes? As far as I know, the utxo set is constructed by each node based on the data in the block (not synchronized with other nodes as is the case with blocks). Please correct me if I’m wrong.