What's Happening?
Ethereum researchers are proposing a new method called 'split proofs' to improve the efficiency and scalability of its blockchain, particularly for 'rapidblocks.' This approach divides a block's execution proof into three distinct parts: `\Pi_T` which
proves transaction execution based on inputs and outputs without referencing a state root; `\Pi_in` which links inputs to a state root; and `\Pi_out` which connects outputs to a new state root. This separation allows the `\Pi_T` proof to remain valid across different state changes, as long as the block's inputs are current. The proposal also introduces an 'input rule' for block validity, where a block is considered valid if its proof is sound, its inputs are current, and its context matches the 'horizon' (a decided past state). This contrasts with previous methods that required re-execution of blocks by validators. The goal is to decouple the agreement on blocks from the agreement on state roots, enabling faster block processing and more flexible state management within the Ethereum network.
Why It's Important?
This development is significant for the future of Ethereum's scalability and performance. By splitting proofs and committing to inputs rather than a pre-state root, the network can achieve more efficient block validation. This could lead to faster transaction finality and reduced computational overhead for validators, potentially lowering transaction costs and improving user experience on the Ethereum mainnet and its Layer 2 solutions. The ability for proofs to 'outlive their state' means that a block's validity is less dependent on the immediate, ever-changing state of the blockchain, making the system more robust and adaptable. This could attract more developers and users to the Ethereum ecosystem by offering a more predictable and performant platform for decentralized applications and smart contracts. The shift also has implications for the decentralization of the network, as it allows anyone to prove an available block, not just its producer, fostering a more open and verifiable system.
What's Next?
The 'split proofs' concept is currently an idea under research, with ongoing discussions and model checks. The next steps involve further testing and simulation to validate the design's properties and measure its performance. Researchers need to address open questions regarding proving latency, the size of data required for proofs (especially read values and witnesses), and the safety of dependencies within the new framework. There are also considerations for how to handle inputs that are not direct values, such as predicates, and the granularity of inputs (per block vs. per transaction). The proposal suggests exploring an 'elastic timeline' where proving time can adapt per block, and a 'slow mode' where the chain can continue even if proving cannot keep up, with confirmation and validity waiting for proofs or re-execution. These discussions will shape the practical implementation and potential impact of split proofs on Ethereum's evolution.
Beyond the Headlines
The 'split proofs' proposal delves into the fundamental architecture of blockchain validation, pushing the boundaries of how decentralized networks can achieve both security and efficiency. The concept of a proof 'outliving its state' introduces a novel way to think about the immutability and verification of blockchain data, potentially leading to more resilient and flexible network designs. This research highlights the continuous innovation within the Ethereum community to overcome inherent challenges in blockchain technology, such as the trade-off between decentralization, security, and scalability. The implications extend beyond technical improvements, touching upon the economic incentives for provers and the overall governance of the network. If successfully implemented, this could set a new standard for how future proof-of-stake blockchains are designed and operated, influencing the broader cryptocurrency and Web3 landscape by enabling more complex and high-throughput applications.
