Vitalik proposes the "Keyed Nonces" solution: may become a new form of state expansion strategy for Ethereum

Foresight News reports that Vitalik Buterin stated, “‘Keyed Nonces’ can not only provide stronger protocol-level support for on-chain privacy solutions, but may also be an important direction for future Ethereum state scalability. By creating storage types dedicated to specific use cases, it is possible to achieve extreme scalability while maintaining protocol decentralization.”

Taking nullifiers in privacy transactions as an example: if on-chain privacy transactions consistently maintain 2,000 TPS, about 500 billion nullifiers will be generated after eight years. Since nullifiers cannot be pruned, putting them all into the existing general state would place tremendous pressure on node storage and decentralization. A dedicated nullifier storage can utilize its highly constrained usage (only for validity checks, and transactions must explicitly provide the nullifier ID), enabling more decentralized processing methods, such as sharded storage (nodes only need to hold a small number of shards and stay connected to the honest nodes of each shard), or Bloom filter optimization (which can greatly reduce verification overhead to about 8 bits per nullifier).

If existing state is still relied upon, builders may have to download tens of terabytes of full data, and privacy users will not be able to efficiently use mechanisms like FOCIL. Therefore, most use cases should migrate to more specialized, lower-cost storage types, while preserving the complete dynamic state for applications like DeFi that require high flexibility, thus achieving a better balance between scalability and decentralization.