Chain Reorganization on Distributed Ledger

[Doan9269]

Chain Reorganization on Distributed Ledger (Chain Reorg)

An injective chain or mainnet run on a specific protocol and follows the rules that every block on the chain strictly gives adherence to the consensus, when a miner create a block and another create the same block on the existing canonical chain, the protocols ensures that the node tend to consider first the block on the longer chain and reject the smaller chain whose block does not follows the consensus for a Reorganization.

This is done in other to ensure all transaction records are validated by following the consensus of the distributed ledger as every transactions were confirmed to be unaltered across all the nodes.

Can Chain Reorganization (Chain Reorg) occur in a multiple of time? how and why?

Does chain Reorg has any negative impact on the fate of the miner's reward and the entire blockchain?

[Charles-Tim]

Can Chain Reorganization (Chain Reorg) occur in a multiple of time? how and why?

The frequency chain reorg is occuring is not often at all, these are the blocks of the last chain reorg and the time it occurred:

Block height                  Date
675392                  20 March 2021
675407                  20 March 2021
685135                  27 May 2021
730848                  07 April 2022
   
Actual Reorganisations: 4 (1 every 71,967 blocks / 485.8 days)

Does chain Reorg has any negative impact on the fate of the miner's reward and the entire blockchain?

No, just that new blocks stop building on old longest chain after a block is mined at the same time by two miners which later lead to new longest chain that new mined blocks are building on.

[o_e_l_e_o]

The frequency chain reorg is occuring is not often at all, these are the blocks of the last chain reorg and the time it occurred:

Two things to note about your statement here.

First of all, chain re-orgs are specific to each node. Let's say Block A and Block B are both mined at the same height. Your node sees Block A first and accepts it, my node sees Block B first and accepts it. If Block B+1 is the next block to be found, then my node carries on as if nothing has happened, but your node (which saw Block A first) has to reorg to discard block A and accept Blocks B and B+1. You have experienced a re-org and I haven't.

Secondly, because of this, there have been many more times that there have been competing blocks at the same height that the data you have used do not capture. For example, I am aware of competing blocks mined at height 723,102 and at 715,276, which are missing from your data.

Does chain Reorg has any negative impact on the fate of the miner's reward and the entire blockchain?

No, just that new blocks stop building on old longest chain after a block is mined at the same time by two miners which later lead to new longest chain that new mined blocks are building on.

It does have an impact on the miners' reward for the block (or blocks) which are discarded from the chain with the lower proof of work; these miners effectively lose their block reward.

[cygan]

and what o_e_l_e_o has explained in the last post, i would now like to show you again visually, so that one or the other can perhaps understand the whole reorg procedure even better

[mocacinno]

Fun fact that's at least a little bit on topic for this discussion: did you know it's not the shortest chain, but the chain with the least cumulative work that becomes stale? In reality, that's allmost allways the shortest chain, but it is theoretically possible that the longest chain has less cumulative work and becomes the stale one

[o_e_l_e_o]

Fun fact that's at least a little bit on topic for this discussion: did you know it's not the shortest chain, but the chain with the least cumulative work that becomes stale? In reality, that's allmost allways the shortest chain, but it is theoretically possible that the longest chain has less cumulative work and becomes the stale one

I was about to point out the same thing.

Where did you get those graphics from? They correctly states that the chain with the most (valid) work is the main chain in one panel, but incorrectly call it the "longest chain rule", and then in two other panels incorrectly refers to chain length again, rather than the accumulated work.

[BlackHatCoiner]

Literally, the "longest chain" isn't necessarily the correct one, but there appear many instances of that word used as synonym to "the one with the most work". In fact, 32 pages long instances. Some people understand the most worked as the longest (i.e., theymos, satoshi), some others like to point out the difference (achow101, Murch, fellow users above).

But "long" refers to length, ergo to height for a chain. It makes little sense to call it long, referring to chainwork. I think we should just stop using the "longest chain", with few exceptions, as it does more harm than good.

Where did you get those graphics from?

I think cygan themselves make it. They've designed similar work for explaining lightning if you check the FAQ thread.

[o_e_l_e_o]

Literally, the "longest chain" isn't necessarily the correct one, but there appear many instances of that word used as synonym to "the one with the most work".

Yes. Lots of people call the most chainwork "longest", just as lots of people call stale blocks "orphans". Such terms are incorrect, though.

Some people understand the most worked as the longest (i.e., theymos, satoshi)

Satoshi uses the term "longest chain" in the whitepaper because when bitcoin first launched, it was indeed the longest chain which was taken as the main chain. Satoshi did not foresee the possible attack where a malicious miner could mine a much longer alternate chain by manipulating the timestamps of their blocks to artificially drop the difficulty to 1 and then churn out blocks as quickly as one a second.

This was changed in version 0.3.3, where height was replaced for chainwork when deciding the main chain: https://github.com/bitcoin/bitcoin/commit/40cd0369419323f8d7385950e20342e998c994e1#diff-623e3fd6da1a45222eeec71496747b31R420

[iBaba]

This is done in other to ensure all transaction records are validated by following the consensus of the distributed ledger as every transactions were confirmed to be unaltered across all the nodes.

Can Chain Reorganization (Chain Reorg) occur in a multiple of time? how and why?

In a multiple time, as in concurrently?
Chain reorganisation typically occurs when two blocks are mined simultaneously.  Any one chain reorganisation can work across an infinite number of blocks, and they commonly do so depending on the conditions.

Does chain Reorg has any negative impact on the fate of the miner's reward and the entire blockchain?

Because chain reorg occurs when a block is removed from the blockchain to make room for a longer chain, it is a negative occurrence for the Bitcoin network and, in particular, for the miner(s) who mined the removed block(s), as they lose the block reward from that block.