Research on ’stateless‘ or ’stateless‘ clients for Ethereum is considered critical to the long-term health of the network, but despite all the progress, some fundamental limitations prevent it from being applied in practice at this time.
At the Unitize conference, Vitalik Buterin, co-founder of Ethereum, provided an update on the latest developments and issues for the transition of stateless clients.
In short, stateless clients are a way of allowing nodes to fully participate in validation without having to maintain all the previous blockchain history. The status represents all the current balances, the smart contract code and their respective data.
The developers of Ethereum 1.x focus on „stateless clients“ to slow down the blockchain
Each new block only makes very small changes in status, but all of them must be checked throughout the block chain, making it a very inefficient process. Stateless clients are the central focus of the Ethereum 1.x initiative, which aims to keep the existing chain in a usable state. But the research also has important implications for Ethereum 2.0:
„In an Ethereum 2.0 sharding context, stateless clients are basically mandatory because the nodes are quickly reorganized into different fragments.
Buterin also noted that stateless clients are also being studied in other block chains, including Bitcoin. Stateless clients rely on cryptographic techniques to calculate only state changes and verify them without having to keep the state in memory. But the cryptography involved is still imperfect.
Ethereum update indicates that version 2.0 is on its way
The problems of creating evidence
The current state-of-the-art solution is based on Merkle’s testing to validate the status through the concept of a token, which includes information about parts of the status that were modified. But the technology has several major drawbacks due to current inefficiencies in Ethereum, which could result in a maximum token size of 405 megabytes for each block.
Optimizations could reduce the token size to a maximum of two megabytes and an average of 600 kilobytes, but that is still well above the current Ethereum block size of approximately 50 kilobytes.
The alternative that Buterin is currently focusing on is Polynomial Undertakings, a test system that relies on polynomial functions to represent data. Through some cryptographic properties, they allow to use only a small token to validate „a lot of values“.
The Ethereum community discusses increasing the block size limit, once again
But he explained that there is a major problem with this approach. Merkle’s tests are easy to update partially because of their tree-like structure, but the polynomial trade-offs require a complete change of the whole curve, which would make the core calculation expensive.
There are a variety of possible solutions to this problem, including, for example, a hybrid „Verkle tree“ model, which combines polynomial trade-offs in a tree-like structure.