Homework on Stale Blocks

Blockchain and Bitcoin 101
#1767
  1. they compete to continue the blockchain
  2. Stale block is an orphan block that is not part of the blockchain anymore, because another one was chosen to continue the chain.
  3. When another block is chosen to continue the block chain
  4. To make sure transactions are not dropped in profit of a longer chain.
#1768

Do you know how one of these competing blocks are ‘chosen’? Why a certain block goes extinct and becomes a stale block. (and their transactions going to the mempool again that aren’t already included in this other block)

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#1769
  1. Both block are valid before final confirmation. Eventually only one will be valid and to be added onto the block chain, the one with the longest new blocks;
  2. A stale block is the one that is dropped off and become invalid once the other block is confirmed to be added as a the new block;
  3. Two blocks are generated at the same time by two different miners;
  4. This is to prevent the situation the two blocks are generated at the exact same time. Upon final confirmation by the longest new blockchain, the other block will be dropped off. This will prevent double blocks to be added onto the blockchain. Transaction is final then and irreversible .
#1770

A stale block was once confirmed. But if 2 blocks are mined on the same blockheight, you have 2 versions of truth with a different block at the end. Then it all depends on wich of those 2 versions the next miner mines a new block on top of it. Wich makes 1 version longer than the other. (longest chain wins)

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#1771
  1. Both blocks get propagated through the network. The nodes start mining a new block on top of the block they have received first.

2 & 3. A stale block occurs when, after two miners mine a block at the same time, the next block is mined on top of one of them. The other one gets rejected by the blockchain and becomes a stale block. All of its transactions come back to the mempool.

  1. To be sure that the transaction has been accepted into the blockchain and cannot be changed.
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#1772

  1. When two miners solve blocks at the same time, there will be 2 versions of the blockchain distributed amongst the nodes. The version of truth that is received by a given node depends on the proximity a miner’s node has to that given node. A new miner will enter the system and mine a new block and depending on which blockchain it appends to that blockchain will be accepted as it is the longest blockchain. The other block’s tx will be returned to the mempool to be mined again, as it will be dropped.

  2. A stale block is a block that was connected to the shorter blockchain that was replaced when a new block was mined and was therefore dismantled.

  3. Stale blocks occur when 2 blocks are mined at the same time and one must be eliminated so that one version of the blockchain exists in the network.

  4. It is important to wait for more than one block to be confirmed as there is no confirmation that the tx your block is in is apart of the only true blockchain in the network. If your tx is in a stale block it may be returned to the mempool therefore rendering it unconfirmed again. This is why 6 block confirmations are advised.

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#1773
  1. Both blocks get propagated out to the nodes.
  2. An orphan block that does not get accepted on the blockchain.
  3. Time lag compared to the accepted block.
  4. To make sure your transaction has truly been accepted as part of the block chain and didn’t end up on a stale block.
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#1774

  1. When two miners solve a block at the same time, their block become versions of truth to their nearest nodes.

  2. A stale block is a block that was not chosen (in the previous comment) by the next miner that created a new block. All transactions on the stale block will return to the mempool.

  3. See above answer

  4. It is important to wait the 10 min standard waiting time for new block creation to avoid the stale block problem

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#1775

Homework on Stale Blocks

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

When two miners confirm blocks at the same time , what happens ? … If two miners solve the hash at precisely the same time then the miner with more network connections to the bitcoin network or other criteria will get accepted by the network first. One will become accepted by the network and the other will be discarded

What is a stale block?

Dropped blocks, orphaned blocks, invalidated blocks

How do stale blocks occur?

There was a longer chain which caused the block to be dropped

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

Because it might be dropped that’s why we have to wait for 6 block confirmation

#1776
  1. Both of the blocks are broadcast on the blockchain at the same time. Miners will then work to append a block to the block depending on the node they get the blockchain from.
  2. When a new block is successfully added, of the two that were broadcast at the same time, the block that the miner appends to is kept since the longest chain is kept. The other block is then dropped and the transactions are returned to the mempool.
  3. When there are two valid competing block transactions, the block that does not get the next transaction added to it becomes the stale block.
  4. You want to wait for multiple blocks to be confirmed to make sure that the transaction is completed and not dropped as a stale block. Transactions in stale blocks are returned to the mempool and will not have gone through yet.
#1777

You basically will end up with 2 valid blockchains with each a different latest block on the latest blockheight. (wich are both valid at this point)
Then it al depends on the next miner, on wich of these 2 versions of truth he will mine his block on top. Wich wil make 1 blockchain longer than the other one. The protocol will always accept the longest chain with most proof of work.

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#1778

  • What happens in the bitcoin network when two miners solve a block at the same time?
    Two versions of the blockchain will exist and the one with the longest chain is chosen.

  • What is a stale block?
    A valid block that was dropped from the blockchain.

  • How do stale blocks occur?
    This happens when there exists more than one version of the blockchain where only one can persist. Therefore, the blocks in the blockchain that wasn’t chosen will become stale (only the ones not already contained in the persisted blockchain).

  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To ensure that the transaction is in a block that does not get orphaned.

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#1779

Both blocks will initially propagate across the network, however, at some point a future block will be appended to one of them before the other, that will cause one of the chains to be longer. Once one of the chains is longer, nodes will discard the shorter one in favour of the larger one, and a single blockchain wil re-establish itself.

A stale block is a block that is ultimately rejected because it is part of a smaller chain as described in 1) above

Stale blocks occur when two blocks that are mined at the same time compete and one is rejected as described above. The stale block is the one that is ultimately rejected

After a block has been confirmed there is still a chance that it will be rejected through growing stale. As further blocks ar mined the chances of this happening dwindle to almost zero, so waiting gives more assurance that a transaction is confirmed.

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#1780

  1. When two miners solve a block at the same time, the determining factor of which block ultimately prevails is the block on the longest chain once the network again reaches consensus. Block on the shorter chain will be discarded.

  2. A stale block is a valid verified block that has not been accepted due to a geographical time lag, being superseded by a longer chain.

  3. Stale blocks occur when they exist on a chain that has been superseded by a longer one.

  4. It is important to wait for more than one block to be confirmed to be confident that the transaction doesn’t exist on a chain with an incorrect ‘version of the truth’.

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#1781
  1. The longer blockchain will win. One blockchain, the shorter one will be dropped.
  2. Stale blocks are blocks that are not accepted into the blockchain network when the winner has been chosen.
  3. Stale blocks occur when miners solve the same block at the same time.
  4. Each confirmation greatly decreases the likelihood of a payment being reverse when sending or receiving a transaction.
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#1782

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Whichever chain is the longest shall be accepted as truth and the other chain should be dropped for it will be a waste of energy.

  2. What is a stale block?
    A stale block is a chain that was once in the block chain but was dropped because of it being short. It is considered a waste of energy and the network usually accepts the longest chain as the truth.

  3. How do stale blocks occur?
    This happens when two blocks has been mined at the same time. If another miner appended another block on one of this blocks and thus making the other one longer. The shorter chain will be dropped.

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

Because that version of truth needs to be propagated throughout the system. Without doing this, your block will be orphaned if no one in the network knows this version of truth.

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#1783

  1. a fork of the chain occurs

  2. blocks that are sent back to the mempool “orphaned”

  3. when the block doesn’t get added to the longer chain

  4. to be sure that block actually added and confirmed 6 times.

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#1784

What happens in the bitcoin network when two miners solve a block at the same time?
When two miners solve the puzzle at the same time, we then have two blocks appended to the blockchain, however, only one of them will be added and one will become an orphan or stale block.

What is a stale block?
It also knows sometimes an orphan block and its a block dropped from the blockchain.

How do stale blocks occur?
The protocol is always to go with the longest chain, so when two miners and it could be more tho this would verge on the impossible. The two miners create a correct block and add it to the blockchain. Then the next correct block is added to only one of the correct blocks thus becoming the longer chain. The protocol is to drop the shorter chain and keep going with the longer chain.

Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
In order to be sure that the transaction has been propagated throughout the entire network, this ensures our block didn’t get dropped.

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#1785

When two miners solve the same block at the same time, the block in the longest chain wins and the other block is discarded or considered a stale block.

A Stale block is a block in the blockchain that is dropped because a another block is produced at the same time in the longest blcokchain.

A stale block occurs when two blocks are produced at the same time and this block is not considered because it is not in the longest blockchain.

It is important to wait for six conformations to make sure that transactions are not dropped from the blockchain.

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#1786

1. What happens in the bitcoin network when two miners solve a block at the same time?
Miners can choose upon which block they solve the next puzzle and the longest chain has most POW and wins

2. What is a stale block?
A dropped block

3. How do stale blocks occur?
When more than 1 valid blockchain exists and eventually one gets dropped

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
It’s possible the chain becomes valid. Wait at least 6 blocks.

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