The puzzle of the selection of Ethereum blocks
As anyone familiar with the Ethereum network knows, choose which transactions to include in the following block is a crucial task for miners. This process is known as “block selection”, and it is essential to understand the underlying mechanics to understand how this works.
A BRIEF BLOCK SELECTION HISTORY
In Ethereum 1.x (that is, before June 2016), the miners had to select all the transactions included in the previous block, regardless of whether it had any possibility of being extracted or not. This approach is often known as a “complete” selection.
However, by July 2017, Ethereum implemented a subscription model called “Selective Full” (SFB). According to this new system, miners are only obliged to select transactions that have a certain level of probability of being included in the following block. In practice, this means that miners can choose which transactions to include in their blocks depending on factors such as:
* Block difficulty : The computational energy number invested by miners and the time needed to solve the block puzzle.
* Transaction complexity : The amount of data stored or transferred in each transaction.
* Network congestion
: The level of network activity, including the number of users, gas prices and block size.
The algorithm
To select which transactions include in their blocks, miners use a specific algorithm that takes these factors into account. Here is a simplified overview:
- Block generation : When a new block is extracted, it is transmitted on the network.
- Validation of transactions : The first 3,300 transactions in the block are validated by nodes and are considered “valid” for inclusion in the following block.
- Block selection algorithm : Miners use their computational power to analyze each transaction based on factors such as the difficulty of the block, the complexity of the transactions and the congestion of the network. They also take into account the hash of each transaction in relation to the previous transactions in the block.
- Block creation
: The selected transactions are combined with any remaining transaction not validated from the previous block to form a new block.
How miners choose which transactions
To choose which transactions to include, miners use a combination of algorithms and heuristics, which include:
* HASH function : Miners use several hash functions, such as SHA-256, to generate hashes for each transaction. They also analyze the distribution of these hash to infer information about the probability that certain transactions are included in future blocks.
* Transaction classification : Miners order their transactions selected by HASH value and then classify them according to their difficulties and other factors.
* Heuristic rules : Miners use predefined rules, such as “if transaction A has high difficulty and low network congestion, include in the following block”, to guide their selection process.
Conclusion
In conclusion, choosing what transactions include in a new Ethereum block is an intricate process that implies analyzing several factors such as block difficulty, transactions complexity and network congestion. By understanding these mechanics, miners can optimize their operations and increase their chances of being chosen for future blocks.