Vitalik Buterin calls lean Ethereum its biggest rebuild since the Merge

But Ethereum now treats replacing every quantum-vulnerable part with a quantum-safe alternative as urgent, Buterin said, including a redesign of the cheap data storage that rollups, the layer-2 networks built on top of Ethereum, depend on.

Privacy has been raised to what Buterin called a ‘first-class goal’ rather than an afterthought. The plan calls for designing core network components so that private, intermediary-free transactions can pass through them by default.

The way the network checks itself is also changing. Instead of every node re-running every transaction, Ethereum plans to rely on recursive STARKs. This cryptographic proof method allows a node to verify a compact proof that the work was done correctly, rather than repeating it. That shift is meant to make the network faster and lighter to run.

As such, the change Buterin flagged as most disruptive is to what Ethereum calls state. State is a blockchain’s current memory, the complete snapshot of everything that exists on a network at a specific point in time.

Think of it as the running record of every account balance and all the data those contracts hold (such as who owns which NFT, how much is in a lending pool, every token ledger), as of the latest block.