Stateless Blockchains: The Future, or Just a Mirage?

cryptonews.com:

In an article released today by a16zcrypto, researchers Miranda Christ and Joseph Bonneau shed light on the intricate challenges of implementing stateless blockchains. Their extensive research delves deep into the complexities of the topic, offering a fresh perspective that promises to shape forthcoming debates in blockchain technology.

In this article, we explore their research on the growth of blockchain states, the challenges of stateless blockchains, and emerging solutions.

Blockchains have been evolving at an unprecedented pace. With the surge in user volume and transaction frequency, the amount of data or 'state' that validators must store to authenticate transactions also increases. 

While Bitcoin's state is limited to unspent transaction outputs (UTXOs), Ethereum's state includes each account's balance and the code and storage for each smart contract. But is the growing size of blockchain states sustainable, and where does the concept of "stateless blockchains" fit into the picture?

The research indicates that Bitcoin nodes currently store approximately 7 GB of data, and Ethereum nodes house about 650 GB. However, as the transaction throughput (TPS) grows, so does the state storage requirement. 

To handle everyday transactions, which could be in the tens to hundreds of thousands of TPS, we might be looking at storage needs in the terabytes or even petabytes. The research suggests this immense storage demand could threaten decentralization by making it hard for individuals to become validators.

The idea of a stateless blockchain is appealing. According to the research, validators would only need to store a constant-sized state, regardless of the number of transactions. This could simplify the process, potentially