Homework on Stale Blocks

Blockchain and Bitcoin 101
#3894

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    When two miners solve the bock at the same time the chain splits in two and the shortest one will be dropped and the transactions will go back to the mempool. The longest chain will always win.

  2. What is a stale block?
    After a fork, it is always the shortest chain.

  3. How do stale blocks occur?
    After a fork, it is the shortest chain. Which will be removed and go back to the mempool.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because it can possibly become a style block if there is multiple versions of truth. It’s better to wait for six blocks because that will ensure that the block containing your transaction is being used on the blockchain and not dropped out of it.

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#3895

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    In a case like this, a stale block is produced as the blockchain temporarily forks until another block is added onto one and the network chooses the longer chain, essentially discarding one of the two simultaneous blocks. All transactions from the discarded block(s) will return to the mempool.

  2. What is a stale block?
    A stale block is a block that is removed from the network and has its transactions invalidated and returned to the mempool.

  3. How do stale blocks occur?
    Stale blocks occur as a result of two blocks being mined simultaneously and producing a fork. This fork is resolved when another block is mined on either resulting chain, as the network accepts the longer chain as truth. The block(s) discarded due to this process are called “stale” or “orphaned” blocks.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Following the rule of 6 confirmations provides a time buffer to ensure that the block you just mined does not end up turning stale as a result of simultaneous mining.

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#3896
  1. The block with the longest chain will attach to the blockchain. The other block will be dropped.
  2. Stale block is a dropped block or orphaned block. The block that gets put back in the mempool to be mined again.
  3. Stale blocks occur after to competing blocks fight to go on the chain and are mined at the same time.
  4. To prevent having your transaction being the stale block and being sent back to the mempool
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#3897

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    They both have a valid block and it gets added to their version of the blockchain and it starts propagating. Eventually one of these 2 chains will be determined as the longest chain and the other one will be dropped as a stale block.

  2. What is a stale block?
    A block or blocks that have been dropped as a result of being a shorter chain.

  3. How do stale blocks occur?
    2 miners solve the nonce puzzle simultaneously and start broadcasting their version of the blockchain. Like Highlander - there can be only one! :wink:

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To make sure your version of the blockchain doesn’t get dropped/orphaned/become stale.

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#3898

  1. What may result from two blocks being mined at the same exact time would be two versions of the truthful blockchain propagating the nextwork.

  2. A stale block is a valid block that has been pruned from the blockchain and its transactions returned to the mempool.

3)This happens when there are more than 1 version of the blockchain and the now stale blocks chain did not end up surviving due to another LONGER chain validating Proof-of-work was accepted by the nodes of the world. This cause the longer chain to keep growing and the short one prunes off the block or blocks that do not agree with the new accepted blockchain.

  1. It would be smart to wait for the blockchains continued growth of what is suggested to be 6 new blocks. The reason for this is due to splits where you have two rather valid chains because of end blocks being produced at identical times and the distribution not reaching the whole network at once. Yet one of these chains will shed its end blocks and return the transactions to the mempool. the chances of you becoming one of these stale blocks is slim but it is even safer to say you “you are not” after at least a few new blocks have been added to your chain. Pretty safe to guarentee you are on the longest chain at that point and well beyond anything that can get pruned off
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#3899
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    There will definitely be a miner who will be faster and make the next block before another miner on another blockchain so now when this winning miner has solved the block, this blockchain now becomes the blockchain with the most work done so even if the other solves the block after, this becomes an orphaned block and is dropped from the network.
  2. What is a stale block?
    A stale block is a block which exists on a blockchain with the least work done and is dropped but its transactions are added to the mempool.
  3. How do stale blocks occur?
    When there is a competing blockchain that has managed to have more work done than the stale block’s blockchain.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    This is important so that transactions do not get dropped, as if they do they will be added to the mempool, so realistically until after a certain amount of blocks are made it is safe to classify those tx’s as confirmed.
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#3900

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    They will be append to the BC and send to nodes around each miner, till there is a conflict and the blockchain with the most PoW will be validate and send to the BC. Meanwhile, the transaction of the stale/orphan block will be added to the Mempool again.

  2. What is a stale block?
    A dropped block because there was a conflict on the BC and the other block has been chosen.

  3. How do stale blocks occur?
    Read 1.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    It’s important to wait 6 blocks, to be sure that our block us validated and won’t be dropped.

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#3901
  1. both blocks are valid and different versions exist on the blockchain until one chain becomes longer with another blocked linked to it. At this point the other block will be dropped.
  2. A block thats get dropped and the transactions go back to the mem pool
  3. A new miner appends a block to one version of the blockchain, this chain becomes longer and the network accepts this longer chain and the shorter chain gets dropped.
  4. best practice is to wait for 6 confirmations. This is incase your transaction is in a block that becomes stale.
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#3902

  1. When two miners solve a block at the same time, the one that gets a new block attached to it becomes the longest chain and is accepted by the network. The other block is rejected and the transactions go back into the mempool.

  2. A stale block is a valid block that was successfully mined and added to the blockchain but got dropped when a longer chain was successfully mined based on a different block.

  3. When a new version of verified blockchain is added, nodes will accept the longest version of the chain and ignore any other existing blocks, sending the transactions they contained back into the mempool.

  4. To make sure your transaction doesn’t end up in a stale block.

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#3903

1.This occurs when 2 miners solve a block at the same time, In such a situation the block with the longest chain is accepted and the other block is discarded or considered a stale or orphaned block. All the transactions are returned to the mempool.
2, A stale block is a rejected block because another block that was produced at the same time was the longer chain.
3. Stale blocks occur after a fork is resolved with a longer chain.
4. It is expedient to wait for 6 confirmations to be certain your transactions are in the accepted blocks and not the dropped chains

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#3904
  1. The chain temporarily splits into two…
  2. A block that is part of a split that never gets appended with new blocks.
  3. When part of the network appends a block to the blockchain and then that version of the block chain is never added too.
  4. To confirm that is genuinely gets incorporated into the main blockchain.
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#3905

1.- When this happens, the PoW will choose the blockchain that is longer with more block confirmation.

2.- Are blocks that were in the blockchain at one point but were dropped because another version of the blockchain was longer.

3.- sometimes we have more than one version of the blockchain and when one version is chosen the blocks of the other version are dropped creating in that moment the so call stale blocks.

4.- Because the system is creating blocks and sometimes different versions of the blockchain, so to be sure that your block is not going to be drop we should wait until at least 6 more blocks are added to the chain.

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#3906
  1. What happens in the bitcoin network when two miners solve the block at the same time?

Each miner appends his new block to the blockchain and propagates his latest version of the blockchain through the network. This means that, temporarily, there will be two versions of the blockchains co-existing in the network.

  1. What is a stale block?

This a block that is part of a blockchain version that has turned out not to be the longest version of the blockchain and is abandoned, i.e. there is another version that has involved more proof of work in the mining process and the network will use that version of the blockchain in the future.

  1. How do stale blocks occur?

A stale block occurs when there are two or more versions of the blockchain that temporarily co-exist in the network and the block belongs to a version that later turned out not to be the longest version. The version of the block is abandoned and the block becomes a stale block.

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

It is possible that the transaction is written in a block that later becomes a stale block. In that case all transactions of this block are invalidated and returned to the mempool, making a particular transaction of that block unconfirmed. If the block containing the particular transaction is followed by multiple other blocks, it is almost certain that the transaction is written in a block that belongs to the longest blockchain in the network and thus the transaction can be considered confirmed.

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#3907
  1. There will be 2 version of blocks. One of them will be the winner.
  2. The block that was discarded by blockchain network.
  3. When there are 2 version of blocks and one of them will be added with the new block, the another will be discarded.
  4. To make sure that our transaction will be truly added in the blockchain network, not on the stale block.
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#3908

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Two versions of the blockchain are created until one becomes longer and has more proof of work, this causes the other block to become a stale block and the txs are returned to the mempool.

  2. What is a stale block?
    A stale block is a block that has been dropped and had the txs within it returned to the mempool.

  3. How do stale blocks occur?
    Stale blocks occur when a block is created at the exact same time by two different miners, causing the creation of two truth to propagate amongst the nodes. The network then needs to resolve this problem by waiting on the next blocks to be created to determine which blockchain will remain as the valid and which of the two blocks will be dropped, turning it into a stale block.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    This is important to allow the blockchain to be advanced enough in number of blocks to ensure that your txs is not within a block that will become a stale block.

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#3909
  1. The chain forks temporarily
  2. A block that gets put back into mempool in favor of chain with more POW
  3. Stale blocks occur after a fork is resolved with a longer chain
  4. In case of a stale block occurring.
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#3910

1- The longer chain after it will be the accepted one.
2- A block that need to be dropped because was accepted by some nodes, but it wasn´t the valid one.
3- When 2 blocks are validated at almost the same time and the closer nodes validates them, however just one of both is link to the next valid block ergo the blockchain.
4- Because of the stale block situation.

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#3911

  1. There is for a short time a “fork” and when another block of one of the two chains is mined before the other the longest chain will be chosen by the network and the block which is part of the shortest side of the “fork” will be abandon and become orphaned block (stale block)

  2. A block that was once in the blockchain but was part of the shortest chain and so was drop

  3. When two miners propagate a valid block at the same time

  4. Because our TX could be on a stale block and be returning to the Mempool

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#3912

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

There are now some nodes in the network that have one version of the blockchain while others have another version (these two versions differ by the most recent block). Because ultimately there will only be one version of the true blockchain, we have to wait for the next block to be added.

The blockchain version onto which the new block is added will be the one accepted as truth because it has more PoW. This blockchain will be the one propagated throughout the entire network. The other version will be ignored and discontinued, and its transactions will return to the mempool.

2. What is a stale block?

The blocks which belong to the discontinued version of the blockchain and were “dropped” are now called a stale block or an orphaned block.

3. How do stale blocks occur?

When two miners solve a block at the same time, you will get stale blocks from the version of the blockchain that has less Proof-of-Work. It is usually the blockchain onto which the next blocks are added the slowest, and it will eventually be ignored and removed from the network, with its blocks becoming stale blocks.

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

This is to prevent your transaction from eventually being in a stale block. If there was only one confirmation required, it’s possible that your transaction was put in the version of the blockchain that would have less PoW. Eventually, even if your transaction was confirmed, it would be put back into the mempool to be confirmed again.

With six confirmations, the blockchain would be longer before your transaction was confirmed. Since the network accepts the blockchain with the most PoW as the truth (in most cases, the longer blockchain), waiting six confirmations decreases the chances of your transaction being dropped later on because it was in a stale block.

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#3913

  1. When two miners solve a block at the same time there will be a short period of time were both are a valid block, when the next miner mines its block it decides which of those blocks it will refer the new one too, as the chain keeps getting longer on one side, the other block that was solved at the same time as the first gets invalid and the transactions of that block gets reversed to the mempool.

  2. A Stale Block is the block that used to be in the blockchain but got dropped out because the other block that was valid at the same time became longer and part of the Blockchain.

  3. Stale Blocks occur when two miners mine a valid block at the same time and one of them gets chosen and worked on further to become the longest. The stale block is the block that gets left behind.

  4. You have to wait for 6 confirmations to avoid the risk of your transaction being in one of the Stale Blocks, by doing so you confirm that your transaction is a part of the Blockchian, the longest chain.

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