What is chain reorganization in blockchain technology?

A blockchain reorganization assault refers to a chain cut up in which nodes obtain blocks from a brand new chain whereas the previous chain continues to exist.

On May 25, the Ethereum Beacon chain suffered a seven-block reorg and was uncovered to a high-level safety threat referred to as chain group. Validators on the Eth2 (now consensus layer improve) Beacon Chain grew to become out of sync after a shopper replace elevated particular shoppers. However, through the course of, validators on the blockchain community have been confused and did not replace their shoppers.

Seven-block reorganization signifies that seven blocks of transactions have been added to the ultimately discarded fork earlier than the community found out it wasn’t the canonical chain. Therefore, blockchain reorganization occurs if some node operators are quicker than others. During this state of affairs, quicker nodes can be unable to agree on which block must be processed first and so they’ll proceed so as to add blocks to their blockchain, leaving the shorter chain when the subsequent block is created.

For occasion, miners X and Y could each find a sound block on the identical time, however as a result of means the blocks unfold in a peer-to-peer network, a portion of the community will see X’s block first, adopted by Y’s block. 

If the 2 blocks are of equal problem, there can be a tie, and shoppers can be given the choice of choosing at random or choosing the beforehand seen block. When a 3rd miner, Z, creates a block on high of both X’s or Y’s block, the tie is often damaged, and the opposite block is forgotten, resulting in blockchain reorganization.

In Ethereum’s Beacon chain reorganization case, up-to-date nodes have been round 12 seconds quicker than validators that hadn’t up to date their shoppers at block 3,887,074. Ethereum chain reorganization happens when up to date shoppers submit the subsequent block earlier than the remainder of the validators. This confused validators about who ought to submit the preliminary block.

Preston Van Loon, a core Ethereum developer, acknowledged that the reorg of the Ethereum blockchain is as a result of deployment of the Proposer Boost fork resolution, which has not but been totally rolled out to the community. Furthermore, this reorganization is a non-trivial segmentation of up to date versus outdated shopper software program, not an indication of a nasty fork selection.