Homework on Stale Blocks

[Vito.crypto]

1. the largest hash blockchain wins. The other TXs (into the other blocks competing) go back to the mempool.
   2.They are the blocks rejected by the network, their tx go back to the mempools
2. They are produced when there is another winner, a longer chain.
3. the ideal is to wait for 6 confirmations.Then, the larger chain wins

[McRiaidhri]

1.The chain forks temporarily ,which ever of these two blocks are then chained to the next mined block the quickest, making it the longest of the two chains wins.
The failed block is dropped from the network, hence the name given… orphaned/stale block.
All transactions from this block is returned to the mempool.
2. A stale block is a block that is mined at the same time as another block, though fails to make it onto the network as it has insufficient POW compared to the other block mined simultaneously to it.
3.By two versions of the blockchain being propagated simultaneously, blocks being produced inside the 10 minute window, before the correct version of the truth has the chance to propagate through the network.
4.To confirm that the block has been accepted by the network, ensuring the block will not be orphaned/stale.

[MatthiasTay]

1. What happens in the bitcoin network when two miners solve a block at the same time?

• Eventually one of the block would be treated as invalid, becoming a stale block when other other block is added with the new block forming a longer chain.

2. What is a stale block?

• Stale block were previously confirmed TX data block but were dropped as there are longer chain in the network

3. How do stale blocks occur?

• it occurs when two or more blocks were added onto the blockchain simultaneously by different miners, resulting in differing blockchains globally. But once either blockchain is added with new blocks, the longer chain becomes the valid one, and the now invalid chain would have those blocks dropped, becoming stale block

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

• allowing sufficient time for the blockchain to be recognised globally by all the network participants

[MagnusB]

1. What happens in the bitcoin network when two miners solve a block at the same time?

If both of the blocks are valid blocks, then part of the network will work on one block and another part on the other, depending on when they receive the new blocks. Eventually a miner will find another block that builds on top of one of the blocks and then that chain will be longer, and therefore chosen by the network as the correct version of the blockchain.
The other block that was not built upon will have all of it’s transactions reversed and returned to the mempool to be picked up by miners to produce new blocks.

2. What is a stale block?

Stale blocks are those blocks that get abandoned because a competing chain became longer.

3. How do stale blocks occur?

Stale blocks occur when there is a conflict between miners on which chain is the correct one, and another competing chain is built upon becoming the longest (correct) chain.

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

Because the block where your transaction was confirmed could still become a stale block, reversing the transaction.

[Monarcha]

1. Both get broadcasted into the network and added onto the blockchain until one of them gets dropped.
2. A valid block that was dropped for another one.
3. If in A-B-c, c is the newly added block, and the miner receives a different blockchain version such as A-B-C-D, then c will be dropped because the network has built a longer chain on top of C compared to c.
4. To make sure that the block will not become stale and dropped off. Newly added blocks can be valid but not confirmed.

[Ikainth]

1. The longer block is selected.

2. A block that was once part of the chain, but has been dropped because the nodes selected a longer block.

3. If the block was not long enough or was produced before 6 confirmations.

4. The more confirmations a block has, the more reliable it is.

[Jake_Hudak]

1. When two miners solve a block at the same time they basically create two new blockchains, whoever’s is the longest gets accepted.

2.A stale block is a block that has the right nonce but is dropped from the blockchain because another block has more PoW

3.Stale blocks happen when a miner is in competition with another miner to make a longer blockchain but then loses and their block gets dropped from the blockchain.

4.Because there’s a possibility that the block you’re in may be dropped.

[mohamed_navvaf]

1. when 2 blocks are solved it will be added to the blockchain creating two different versions of the blockchain.
2. Stale block is a block that has been dropped of the blockchain due to it not being on the longest chain.
   3.when there are two chains, once the next miner adds the block to once chain, the blockchain with the longest chain will be passed on and the other last block on the other chain will be dropped and all tx will go back to mempool.
3. To make sure the block with your transactions are on the longest version of the chain and it does not get dropped off the chain like an orphan block.

[Robert_Harris]

A temporary fork in the block chain is created
A Block thats longer is disgarded.
When two miners go to mine the same block and one is sent back to the mempool
The transaction gets rejected

[Maki]

@Robert_Harris

The transaction gets rejected

Waiting ensures your transaction is not part of the stale block.

[LuisM]

1 – Both blocks will be added to the blockchain but after that some nodes will receive/see one block and other nodes will receive/see the other block. Eventually another miner will be mining a new block picking from only one of the two previous blocks. The block that was not picked will be droped from the blockchain and the transactions in it will be sent back to the mempool.

2 – A stale block is a block that was valid but was droped from the blockchain.

3 – A stale block occurs because it was added to the blockchain but its hash was not included in the next valid block added to the blockchain. In this case the stale block will not be part of the chain with the most work put into it.

4 – Because the block with my transaction might be valid but then droped from the blockchain becoming a stale block.

[lanwan]

1. both blocks will apend the network, but eventually one becomes stale

2. a block that was added to blockchain but not the longest one

3 when competing miners add blocks on near the same time and change is propogated to other miners

4. to prevent stale blocks

[Digitally]

when 2 miners make a block at the same time then one will win and the other will become a stale block
a stale block is a block that has nothing in it since all of the transactions are in the mempool
stale blocks occur when 2 blocks get sent to the chain at the same time
it’s importAnt to wait because the transaction might get sent to the mempool and that will slow it down

[RobF]

1. A portion of the nodes confirm one block, and another portion confirms the other block. 2 separate blockchains are formed. Whichever block chain subsequently becomes the longest by adding additional blocks (based on PoW, not the number of new blocks) will become the one true blockchain. The other new block of the other blockchain will get dropped off and its transactions go back in to the mempool.

2. A stale or orphaned block is one that is confirmed by a portion of the nodes on the network but not all nodes and is eventually dropped and all of its transactions go back in to the mempool.

3. When 2 miners create a new block at the same time one will become stale. Whichever block has a shorter subsequent blockchain (based on PoW not the number of blocks) will become the stale block.

4. Requiring multiple block confirmations ensures that a confirmed transaction is part of the one true blockchain rather than part of a stale block that gets dropped off back in to the mempool.

[Matty_G]

1. What happens in the bitcoin network when two miners solve a block at the same time? When the next Miner in the network chooses one of the two blocks and her new block is longer than the other, the shorter block will be removed. This ensures there will always be one version of truth on the blockchain.

2. What is a stale block? A dropped block that have been removed from the blockchain due to a competing block having longer PoW

3. How do stale blocks occur? Two blocks were created at the same time. As a result each separate network of nodes have their own versions of truth. One block over time achieves longer PoW. the other “stale” block is then removed from the network. There can only be one version of truth on the Blockchain

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? It minimizes stale blocks - information needs time to travel physically global through the network. Ideally you should wait 6 confirmations. 6 blocks after your block

[rjreddog]

1. What happens in the bitcoin network when two miners solve a block at the same time?

The block that does not get chosen next to propagate or lengthen the blockchain will be removed and returned to the mempool. The block that is chosen by the next miner continues its journey onto the blockchain

2. What is a stale block?

Is a block that has been sent back to the mempool. A block that will not be included onto the blockchain.

3. How do stale blocks occur?

Stale blocks occur when two blocks from two separate miners complete a block at the same time. The block that is chosen by the next miner continues onto the blockchain while the remaining block gets removed and placed in the mempool.

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

To give sufficient time to propagate the blockchain data across the worldwide Bitcoin network and to make sure that your completed block is not a stale block.

[yusunu33]

1. The network deems both blocks as valid however it will accept the block that has the longest chain in terms of proof of work and mining difficulty.

2. A stale block is a block that was on the blockchain however it was then dropped from the blockchain.

3. A stale block occurs when it is not part of the longest chain, another chain has a longer chain in terms of proof of work

4. It is important to wait for the network confirmations of additional blocks because it keeps all nodes in sync and up to date with the latest blockchain info. It prevents blocks from being mined too fast which would result in many dropped blocks.

[Jonesy]

1. What happens in the Bitcoin network when two miners solve a block at the same time?
   The longest blockchain wins while the other is orphaned and returned to the mempool.

2. What is a stale block?
   Stale or orphaned are not finalised on the blockchain in the accepted time. They are returned to the mempool to re-complete the network process.

3. How do stale blocks occur?
   Congestion on the network creating time delays >10 minutes.

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
   This ensures that your transaction is not on a block that is dropped and returned to the mempool.

[Given]

1. What happens in the bitcoin network when two miners solve a block at the same time?

Both blocks will be propagated onto the network and can exist at the same time until another block is appended to either one of the blocks. At which point the shorter blockchain will cease to exist and the transactions within the corresponding block will be added to the mempool once again.

2. What is a stale block?

A stale block is a block that is at the end of a shorter blockchain once the longer blockchain is propagated through the network.

3. How do stale blocks occur?

At first 2 miners will mine a new block at the same time, in a way creating 2 a split. Once another block is mined on either of these blocks that will be the longest blockchain (1 new block vs 2 new blocks). Once this new block is propagated through the network the block that is on the other side of the split is now stale.

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

Because it could happen that your transaction is in a stale block.

[Josh_Siv]

1. When two miners mine two blocks at the same time, the block to have another block added to the new chain is now registered as True and the other block that did not recieve the newly added block is returned back into the mempool.

2. A stale block is a block that has been discarded from the block chain due to another block being registered as true.

3. Stale blocks occur when two newly added block are added to the block chain and one of those truth is then discarded due to the other newly added block having more block ahead of it than the other said block.

4. It is important to wait for more than one block to be added to the chain because it gives the system time for other blocks to propegate and shows that the longest chain is the real truth.