Homework on Stale Blocks

Blockchain and Bitcoin 101
#241

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Both blocks will be noted but the one with the longest chain will be accepted to the block chain.

  2. What is a stale block?
    Stale blocks are blocks that was noted or was in the short chain and were dropped from the block chain.

  3. How do stale blocks occur?
    By having two or more versions of the truth.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Allowing for 6 or more confirmation will ensure that more POW was put in to ensure the security or truth of a block/ longest chain.

#242

If two miners solve the block at the same time two different versions are temporarily propagated to the nodes. The situation is saved as the next block is produced because the output hash of one or the other of these two blocks will be in the new block. As this longer chain is propagated to the nodes any transactions in the last block (the duplicate or stale block) on the shorter chain will return to the memepool. It is important to wait for several confirmations (ideally 6) to ensure your transaction wasn’t in a slate block and has been permanently included in the blockchain.

#243
  1. the network is split. There are 2 versions of the truth.
  2. Stale blocks, are block that were once in the chain but have been drop from the chain, because that version of the chain wasn´t the longest, so the other version was accepted from the network it was faster.
  3. they occure when we have two versions of the chain. then one version gehts faster longer so the other version has to be dropt. Those Block that have now been dropt are called stale blocks.
  4. because it could be that your Tx is in a block is in a version of the blockchain that is not the longest any more and sooner or later will be dropt. If we wait for 6 confirmation we could be sure that our transaction is confirmed.
#244

  1. The solutions are propagated through the network and other nodes pick up the new block and add it to the blockchain. Miners start to work on the solution for the next block. However, there are now two versions of the blockchain on the different nodes on the network. Nodes validate the “correct” blockchain by choosing the longest chain.

  2. A block which was correctly mined, but was later invalidated.

  3. Two or more blocks are solved at the same time, but then later dropped by the network since there is a solution with a longer chain.

  4. A block might be invalidated if a solution to another block was found at the same time. If the transaction was not included in the other block as well then it is returned to the mempool and the transaction never took place. The more blocks that are added after a block the stronger the confirmation of all the transactions within that block.

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#245
  1. The network will accept the longest blockchain and will drop the other one
  2. A valid block that has been discarded because it didn’t propagate fast enough
  3. They occur when miners mine valid blocks around the same time. The network ends up picking up the one that propagated fastly, the other block then is discarded and becomes a stale or orphan block
  4. To make sure the transaction is accepted in the blockchain and not labeled as a stale block
#246
  • What happens in the bitcoin network when two miners solve a block at the same time?
  • What is a stale block? It is a block dropped from the block chain
  • How do stale blocks occur? When two miners validates a block chain at the same time. A stale block occurs when one block chain is longer than the other in which case the loosing miners gets dropped .
  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? It it important because of possibility of be dropped and becoming stale.
#247

It’s not really the matter about propagation speed. If for example only a few nodes have a certain block and by incident 1 of those few nodes finds already a new solution for the next block on top of it, this wil be valid while another competing block was maybe propagated on more nodes already. the rule is ‘the longest Chain wins’

#248

What happens in the bitcoin network when two miners solve a block at the same time?
Both blocks propagate throughout the network with some nodes excepting one or the other.

What is a stale block?
This is a valid block which has ceased to become part of the longest chain.

How do stale blocks occur?
When two miners create a valid block at the same time and both are propagated through the network. When only one of these is accepted in the next block the non accepted one becomes stale as the chain with the highest PoW takes precedence.

Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
This is because the first block might not be the only valid one in existence and if it is not included in the next block it will become stale and transactions in it invalid. Although there is a good chance they are in the other valid block or will be included in the next block. Waiting for a few confirmations is the best practice with up to 6 confirmations for large transactions.

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#249

When two miners solve a block at the same time, each block is appended to the chain and sent to the geographically-nearest nodes. As it takes time to propagate the updated blockchain around the entire globe some miners will see different versions of the chain. The next block will be solved about 10 minutes later and appended to whichever version of the chain happens to be closest to the winning miner, so that particular chain is now the longest chain. Miners will always append new blocks to the longest chain, so the other version of the blockchain will be dropped and its last block would be called an orphan or stale block.

A stale block is one that was attached to the blockchain but overruled by successive blocks. Stale blocks are dropped from the chain due to the longest chain rule, which states that the longest chain having the highest difficulty is the truth. Only one chain can claim to hold the true history of all the transactions.

A stale block occurs when another block is found at the same time and linked to a competing version of the blockchain. Whichever version of the chain becomes longest will be selected by miners to build upon. The chain version that is shorted will be dropped.

Stale blocks can and do occur so it’s wise to wait for 6 blocks to be recorded before calling a transaction confirmed. If you only waited for one block, your transaction could have been included in a stale block that would be dropped from the chain which means your transaction didn’t go through as intended. The transaction would be returned to the mempool and eventually included in a different block.

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#250

  1. The nodes will accept either one or the other. Eventually, a new miner will accept one block on one node and continue the chain, and eventually mine the next block. The network will then choose whatever the longest block as the only version of the truth, and propagate that to all nodes around the world.

  2. A stale block is a block mined by a miner that was not accepted by all the nodes in the network.

  3. A stale block happens when two miners make different new blocks and one block is rejected because it was not part of the longest chain by other miners.

  4. It’s important to wait because any pending transaction could eventually be put in a stale block, and that would return to the mempool as an unconfirmed transaction until the transaction is confirmed in a block that is accepted by the entire network.

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#251

Depending on which of the two blocks miners continue to add blocks to will prevail. The other block transactions will be returned to the mempool.

When two miners solve a block at the same time, the one of those two blocks with the shorter chain will be removed. That is a stale block.

They occur when a valid block (a block that has been confirmed at the same time as another copy of the same block) gets dropped due to a longer valid chain.

Because of stale blocks occuring. If your transaction is in a stale block, the tx will be returned to the mempool. To be totally sure your transaction is valid you need to get 6 confirmations.

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#252

1.Two parallel versions of the blockchain are created.
2. It is a block that is dropped of the blockchain, because it belonged to the shorter chain.
3. They occur by being drop from the blockchain.
4. Because that block might become stale.

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#253

  1. The blockchain will separate in two chains and in the end the longest chain with verifyied information will remain and the other other blocks will go to the mempool.

  2. The stale block is the name of the block in the previuos example which goes to the mempool as un still not yet confirmed/valid block.

  3. Stale blocks occur when a block was valid for a while but get dropped to the mempool on behalf of another block that was confirmed and approved to the blockchain.

  4. The network with computers/nodes has to confirm and accept a new block to the chain meaning that when consensus is reached in the network the block will be added to the blockchain.

#254
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    2.What is a stale block?
  2. How do stale blocks occur?
  3. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

1.It will be two blocks. One will be the right on the longest one and the other goes to the mempol.
2. The block that get dropped from the blockchain went to the mempol.
3. When two miners mine same valid block at the same time.
4. You need to wait for 6 confirmations the be sure its valid and will not get dropped to the mempol.

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#255

The chain splits into two, the longest chain is then accepted and one of the blocks will be dropped.

A stale block is a block that has been dropped for a chain with a longer POW.

A transaction could be in a stale block and be dropped from the chain if you do not wait for 6 confirmations which take about 10 minutes.

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#256
  1. The next miner who finds the correct nonce chooses one from the previous two blocks and with the previous hash and nonce creates a new block which is deemed the lonest chain.
  2. A stale block is a dropped block that has its transactions sent back to the mempool.
  3. Stale blocks occur when the next miner records the blockchain of record not using data from nodes using the stale block. If a transaction does not get 6 confirmations it was in a stale block and is sent back to mempool.
  4. To make sure the TX your sending or receiving is not in a stale block.
#257

  1. when two miners simultaneously solve a block, two chains are created, both of which are correct. It then depends on which block the next miner continues with. This will be the longest chain that will be used to connect the next blocks. The other block(s) or chain expires and this is called a stale block or orphaned block. The transactions processed in those blocks go back to the mempool

  2. a stale block is a block that was originally in the blockchain, but because two miners have mined a block at the same time, creating a double chain, the longest chain will continue to exist. A stale block was therefore part of the shortest chain and is canceled

  3. a stale block occurs when 2 miners mine a block at the same time, but the blockchain continues on the other and longer blockchain

  4. It is important to wait for 6 confirmations to ensure that the block your transaction is in, is not removed from the chain.

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#258

Answer:

  1. The closest node to a miner starts adapting that next block. It creates a situation when the network has two different blocks. However, if the next block is added to one chain, the other is automatically dropped. It is called a stale block. The network adapts the longer chain.
  2. A stale block was valid on the chain but has been dropped because there is longer blockchain on the network.
  3. Stale blocks occur whenever the other chain of the same height had its blockchain extended first. The network will adopt the longer chain and drop the shorter. At this point stale block occurs, which means all the transactions in that block go back to the mempool.
  4. Because the block which has your transaction can become a stale block. Your transaction returns to the mempool until the next miner picks it up. Since the information has to travel to each node, it takes time for nodes to sync their blockchains. By that time, more than one block can become stale.
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#259
  1. What happens in the bitcoin network when two miners solve a block at the same time?
  • When two miners solve and block at the same time, the blockchain will split into two directions. However, there can only be one “truth”; thus, the miners will need to verify which block will be the best fit to amend into the chain.
  1. What is a stale block?
  • A stale block is when a non-confirmed block is dropped from the blockchain due to the unfitting requirements of the entire blockchain.
  1. How do stale blocks occur?
  • Stale blocks occur when there are miners solving for two different blocks. Since the two blocks are leading into different directions, they other miners will then link other unconfirmed blocks onto the two previous unconfirmed blocks. Thus, there are two new links of unconfirmed block rows. One row must be dropped since there can only be one truth.
  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
  • It is important to wait for more than one block to be confirmed when sending or receiving a transaction since your block can soon become a stale block. It is wise to wait for six other confirmed blocks after yours to officially consider it “confirmed.”
#260

  1. Both versions of the blockchain gets propagated through the network. Eventually more blocks will be mined on top of it and the longest chain will win.

  2. A valid block that was mined but then lost out to another block because the chain that it is on ended up being shorter.

  3. Competing miners are mining on different versions of the blockchain, eventually one version ends up being longer and the other versions are discarded, i.e. the block become stale.

  4. There is still a chance that the blocks will become stale and the transaction might go back to the mempool and not enter the blockchain.

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