Homework on Stale Blocks

[Mauro]

@Dylan22

1. Both blocks will start to propagate through the network.

Its important to note that the chain is split at that point of time.

[Lucky_Mkosana]

1. Two versions of the truth are being circulated but the network will support the longest blockchain with the most PoW and the block with the weak PoW is moved to the mempool.

2. A stale block is a dropped block that was in the blockchain - orphaned block.

3. The block with the weaker PoW becomes a stale block.

4. Important to wait for 6 confirmations to come after your block to make sure it’s not dropped.

[Mauro]

@TaahirCrypto

1. depending on which block the next miner chose 1 block will be invalidated.
   2… a stale block is the block that gets invalidated when 2 blocks were mined at the same time, it is a emty block that disconnected from the blockchain.
2. when two miners mine 2 blocks at the same time, one block gets droped in the next 10 min as soon as the next block is mined, the droped block is then called a stale block.

1. Miners don’t choose blocks, they mine them. They can of course choose what transaction they put in. The important thing to know is that when 2 blocks are mined at the same time, the blockchain splits. There is now 2 different versions of truth.

2. A stale blocks can’t be resolved if 2 blocks are mined at the same time. Actually if it happens twice in a row, the next time a miner mines and successfully propagates it to everyone there will be 2 stale blocks. A stale block is a block that was once a part of the blockchain, it was never empty. Its transactions go back in the mempool.

3. It can always happen twice in a row. So it could take 20 minutes if we take an average time of a block. That’s why we wait for 6 confirmation as the likelihood of it happening 6 times in a row is very unlikely. This would have been an answer to the 4. question in a way.

Hope that helps.

[Mauro]

@Anarchocapitalxx

1. The longest blockchain will prevail

Yes, the network will eventually accept the longer chain. But what exactly happens when 2 blocks are mined at the same time? The current blockchain gets split in 2, creating two valid chains in which one part of the node accepts one truth and the other nodes the second truth.

[Mauro]

@JonathanGroschel

4. Becouse the risk of having your information in a stale block decreased with the added blocks. (6 blocks is the golden number)

I like how you mention that it decreases with every block that gets added. Nice perception.

[Mauro]

@Davide_Coltro

1. After that, another miners wants to create the block; so if he chose the block of the first miner, the blockchain is the first, if he chose the block of the second miner, the blockchain is the second.

All of that is true, but the question is what exactly happens at that moment. The answer is that the network will have 2 version of truth. The chain itself will fork in 2 for a short period of time until the network resolves it by waiting for a new block.

[Neeraj_Nerlekar]

1. The blockchain has two blocks propagating through the network at the same time.
2. Stale block, also known as an Orphaned block, is the shortest link to the blockchain when two blocks are created at the same time.
3. When two blocks are created at the same time, and the block among the two, which adds more POW, becomes valid. The shorter block becomes the stale block and gets rejected.
4. In order to avoid having your transaction on the stale block, it is essential to wait for at least 6 confirmation to be accepted on the blockchain.

[Mauro]

@shanemulv

1. When 2 miners solve a block at the same time the longest chain wins.

@shanemulv

3* It is the block with the shortest chain

1. If two block get solved at the same time the chain will split and bot of them will have an equal lenght. Meaning that only after a new block is mined that he longest chain will take over.

2. The question was about how they occur. They occur when 2 miners solve a block at the same time. After that a new block will be mined and the chain that got it will take over, leaving the last block in the other chain to become a stale block.

[Adam1]

1. It starts 2 different versions of the truth

2. A stale block is the loser of the race between two different versions of the truth in a blockchain.

3. When 2 different versions of truth occur, there’s a race to see which truth gets the next block. the loser of that race becomes the stale block.

4. because the network needs to propagate the information and make sure its not a stale block.

[FlippingDave]

1. What happens in the bitcoin network when two miners solve a block at the same time?
   They both get put on their persepctive chains until one grows longer and wins the other. His trans go back to the mempool.
2. What is a stale block?
   Those in the shorter chains that get dropped.
3. How do stale blocks occur?
   when they failed to grow stronger child blocks than those the same age as them.
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
   Chances it’ll go stale are high otherwise.

[Dylan_Robertson]

1. Bother miners will transmit their blocks to the network. Some nodes will regard the block received from miner 1 as the current block and other nodes may consider the block from miner 2 as the current block. This causes a split in the blockchain.

2. A stale block is a block which is orphaned due to a chain split.

3. When there is a split in the blockchain, the network will recognize the chain with the longest accumulated proof of work to be the correct chain. The competing chain will then have its blocks orphaned. The transactions contained in orphaned blocks will be sent back to the mempool to be included in new blocks on the correct chain.

4. When a transaction is confirmed in a new block, there is still a chance for that specific block to be orphaned if another block is found simultaneously. More transaction confirmations increase the likelihood that the block will be kept in the blockchain without being orphaned.

[cryp2]

@ivan

• What happens in the bitcoin network when two miners solve a block at the same time?
• What is a stale block?
• How do stale blocks occur?
• Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

1. The one who solve faster and the one who have longest block wins. the one loses will drop the block

2. Stale block is the other word for dropped block. It is a block that did not append on blockchain or the block that not linked on the longest block.

3. To minimize the risk of stale block.

[Hackerman]

1. They are appended to the blockchain and two parallel versions of blockchain exist for some period of time.
2. Stale block is a block that was in the blockchain but was dropeed because it didn’t belong to the longest blockchain.
3. Stale block happen when a block gets dropped.
4. Because we want to be sure that our transaction will not end up in stale block.

[Brijay]

1. When two miners solve a block at the same time a temporary fork will be created as some nodes will receive one version of of the blockchain (with Block A on it) while other nodes will receive a different version (with Block B on it). Miners will then most likely begin to add further blocks to each leg of the fork. The first block to have another added to it will be adopted and the other will be dropped (orphaned).

2. A stale block is a block that was initially accepted onto the blockchain because it was mined simultaneously with another block, but was then dropped back into the mempool because it was on a leg of the resulting fork which was discarded.

3. Stale blocks occur by having two or more blocks accepted onto the blockchain at the same time and then one of those blocks being dropped. The one which is dropped is the stale block.

4. It is important to wait for more than one block to be confirmed when sending or receiving a transaction because there is no guarantee that a block will stay on the blockchain even though it has been accepted by the network. This is because a fork may have occurred and the transaction could be on the dropped leg of the fork. Therefore the transaction could still fail to complete even after a block confirmation.

[Richie]

1. A temporary fork would occur on the network. Ultimately th next miner would then add their block to the network and the longest chain wins. The other block is then stale or orphaned and dropped. The transactions contained within the dropped block return back to the mempool.

2. A stale block is a block that has been dropped by the network.

3. A stale block occurs where two miners solve the hash at the same time, adding two block and creating a fork. Ultimately the one with the longest chain wins and the other block is then dropped, or becomes - Stale.

4. To reduce the risk that the block that contains your transaction isn’t dropped by the network. Ideally you should wait for 6 transactions to confirm.

[Coco]

1. Two versions of the truth is created. Finally one block will then win, when a new block is created and added to the blockchain because this chain is then longer and has more PoW.

2. A stale block is the version of truth that “looses” the race to create the next block and therefore gets erased from the blockchain and all transactions from that block goes back into the mempool.

3. Stale blocks occur when two blocks have valid transactions and valid nonces that are below the target. But there can only be one blockchain and when the longest chain wins (with most PoW) the other block becomes a stale block.

4. Because you want to make sure that your transaction does not end up in a stale block that gets sent back into the mempool. That is the reason why you should wait for six blocks to have a confirmed transaction.

[hubitutl]

1. What happens in the bitcoin network when two miners solve a block at the same time?
   A fork of the chain is the result.

2. What is a stale block?
   A fully mined block that is no more part of the chain.

3. How do stale blocks occur?
   They are the byproduct of resolving the fork. Because only the version with the block that gets created next will be continued and therefore the blocks of the other chain get no more considered by the network.

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
   So we can be sure that it goes through and doesn’t end in a stale block. This is based upon the rule that the longest chain always prevails.

[ajphminer]

1. There will be two versions of the blockchain

2. A stale block is a valid block that resides in one version of the chain but has been dropped because it is not connected to the longest chain. It is then sent back to the mempool.

3. Stale blocks occur when multiple blocks get mined at the same time creating multiple versions of the chain.

4. Multiple block confirmation is recommended to make sure that the new block is appended to the longest chain and avoid being orphaned.

[hoolie]

1. Both blocks are propagated around the network creating two blockchains, the longest blockchain will be concidered truthful and accepted by the network, all other blocks will be disregarded and transactions droped back into the mempool.

2. A valid block that was created at the same time as another but was dropped due to another block having a longer chain

3. When 2 miners guess the correct nounce at the same time

4. To make sure your block has not been dropped by the network

[Lard_Bodum]

1. One of them, completely by chance, will “win” and have their block appended to the blockchain. This might be because one of the “versions of truth” will propogate faster through the network, or maybe a 3rd miner has solved the puzzle and is trying to append their block using the “version of truth” of one of the former miners thus making that version of the block longer. The blockchain always chooses the longer chain.

2. A stale (or orphaned) block is one that was appended to the chain but did not last the 6 confirmations (6 blocks after it) thus it was was dropped and its transactions are returned to the mempool.

3. Due to the blockchain having varying versions of the truth, a new block is not fully confirmed until it has lasted for another 6 blocks after it. If it didn’t last the 6 confirmations it is dropped.

4. Because there can only be one “truth”, ie, one version of the blockchain that is verified and accepted by the network - consensus. This also relates to block time where the mining difficulty varies to regulate it to 10mins, ie, a new block is created every 10mins. This allows sufficient time for it to propogate throughout the entire network. 6 confirmations means 60mins before a block is fully confirmed.