Homework on Stale Blocks

Blockchain and Bitcoin 101
#3611

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    there are two blocks that could be added to the chain but only one can

  2. What is a stale block?
    a block that was mined but then rejected from the chain

  3. How do stale blocks occur?
    when a block that was mined concurrently stays because it is part of the longer chain

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    to be sure that the block containing the transaction stays on the chain and does not get orphaned

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#3612
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    one will eventually be added to the blockchain. The shortest confirmed blockā€™s will be dropped and the miner with the longer confirmed blockā€™s will be added
  2. What is a stale block?
    Blocks that get put back in the mempool because another block was added with longer chain of confirmed blocks
  3. How do stale blocks occur?
    When a block is valid for a period of time because 2 blocks were produced with the same version of truth but then later dropped because the chain continued on another block with a larger number of confirmed blocks
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Standard to wait for at least 6 block confirmations to ensure your transaction is not dropped and added to another block
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#3613
  1. the longest chain becomes accepted in the system
  2. stale block is an unaccepted block in the chain b/c another block was created at the same time and was picked up by the next block after.
#3614
  1. stale blocks occur when 1 of 2 blocks of the same time are created, next block picks one then the other becomes a stale block
  2. you should wait for 6 blocks so you can be almost assured your block will continue to be the valid block in the chain.
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#3615

  1. When two miners produce a block at the same time, two versions of the truth are formed in the chain and both are equally valid.

  2. A block that was removed from the chain and returned to the Mempool.

  3. When a new miner produces a new block and adds it to one of the two possible ends of the chains, the other block becomes a stale block.

  4. To make sure that the block is not a stale block or that the selected chain is not built on a stale block.

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#3616

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    If 2 miners solve a block (block A, block B) at the same time a new miner solves a new block (block C), the miner will attach block C to block B or A, let say that he picked block A. The miner will continue to propagate the chain with A and C block, all the tx from block B will be returned to the mempool.

  2. What is a stale block?
    A stale or orphan block is the bloc that is hashed in a correct manner but not accepted by the network.

  3. How do stale blocks occur?
    Stale block occur when 2 miners calculate a correct block at the same time. The miners chose one block and continue building the chain on it. The other one is not accepted and the TX-s inside are put 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?
    It is necessary to wait to see if the block was accepted or to see if it became a stale/orphan block.

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#3617
  1. When two miners solve a block at the same time each chain will get sent to the nearest nodes, but essentially whichever chain grows longer first will be the one that is propagated throughout the network and the other block on the shorter chain will be sent back to the mempool.

2.The stale block is the block that was initially accepted, but was ultimately rejected because of the situation described above where two blocks were accepted at the same time.

3.I believe I explained that aboveā€¦

  1. Waiting for more than one block to be confirmed gives the network time to sort out which blocks are actually being added to the chain and which will be rejected.
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#3618

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

  • Both blocks are appended to the blockchain, they have valid nonce and transactions, so two versions of the truth exist - depending on where you are and which network node is queried.

What is a stale block?

  • A block that has not been accepted by the network yet (due to network propogration and node proximity), it is unconfirmed and hence is not a part of the valid blockchain.

How do stale blocks occur?

  • The miner adding a newly created block chooses to add it on an available nearby node. Hence, the block that was created at the other network node becomes stale and remains unconfirmed. :roll_eyes:

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

  • You do not know until you have at least 2 confirmations that your transaction has been accepted as part of the valid blockchain by the network. :slightly_smiling_face:
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#3619
  1. The network looks for the longest chain so in a tie, the network would look for the next solved block and drop the tie block which does not match.
  2. A tie block that is dropped from the chain - a rejected block.
  3. They occur when the next block being built builds off of a different block.
  4. It is important so that the block information can be propagated through the system to verify proof of work and to avoid the chain being broken.
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#3620
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    = Block with higher Pow will be added to the blockchain and the other block will be added to the mempool.
  2. What is a stale block?
    = It is a block that was not given priority because of less Pow as compared to the other block, removed from the chain and was put into the mempool.
  3. How do stale blocks occur?
    = When 2 miners solve the same block, the block which is removed from the chain becomes a stale block.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    = The block of the losing chain is retuned to the mempool hence we should wait for 6 confirm blocks in the chain.
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#3621
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Longest one gets adopted
  2. What is a stale block?
    Orphaned block that was dropped and returned to the mempool, another block was acepted as the truth by the nodes
  3. How do stale blocks occur?
    Block was dropped because another one got added to the blockchain
  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 transaction / lock does not get dropped or orphaned, needs to get accepted by the nodes
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#3622

  1. From that point, there will be two blocks connecting to the previous block. These two blocks are valid but not confirmed yet.

  2. Stale block is a dropped block from the blockchain.

  3. It occurs when the other longer blocks are chosen by the network.

  4. Because that block could end up getting dropped out from the blockchain. Confirming unconfirmed blocks can lead to transaction rejection afterwards.

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#3623
  1. What happens in the bitcoin network when two miners solve a block at the same time?

They will propogate their blocks to the network but only the block with the high pow will be accepted and any transaction in the other block that were not included will be returned to the mempool

  1. What is a stale block?

A valid block that was dropped due to it not being in the longest chain (highest POW) vs another version of the blockchain

  1. How do stale blocks occur?

Stale blocks occur when the following mined block does not use this block and instead uses another mined block

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

The possibility of the block with one confirmation becoming stale is greatly reduced

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#3624

1- two versions of the block will be created until the one of them goes to back to mempool, the networks always prioritize the longer block

2- a functional block that had to go back to mempool due to the network choosing another version of the block that got a continuation block.

3- When a block gets chosen by the network the other block gets stale or put aside and not being included on the main blocks.

4- so at least 6 confirmations will be in motion, and all the nodes will get the new block.

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#3625

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    My answer: Both blocks get added to the blockchain. The next miner decide by chance, which blockchain is the truth.

  2. What is a stale block?
    When there are two blocks added to the blockchain at the same time, which sre both valid blocks validated by other nodes, we have to wait until the next miner of block decides by chance which blockchain is the truth. The block of the other blockchain is now dropped back to the mempool, as it is not the longest blockchain anymore. The dropped block is called stale block or orphand block.

  3. How do stale blocks occur?
    My answer: See answer 2.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    My answer: In order to prevent stale blocks.

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#3626
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Two Blocks/truths will be added to the Blockchain. The longest chain gets adopted, then other block is returned to the mempool.
  2. What is a stale block?
    Blocks that were in the Blockchain, but that got dropped --> back to mempool.
  3. How do stale blocks occur?
    When two miners create a valid block, but the block didnā€™t end up in the longest chain.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To minimise orphaned blocks, block needs to be able to propagate to the entire networkā€“> 10 minutes
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#3627
  1. the fastest and logest chain will win
  2. it is block which is not confirmed into blockchain
    3.when some miners mine a block at the same time 1 block can win
    4.we should wait for 6 new block to make sure the block contains our transaction
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#3628
  1. When two miners solve a block at the same time the blockchain is temporarily forked. Whichever block is appended to next will become the single source of truth and the other block will become stale.
  2. A stale block is a block that has been dropped from the blockchain. All the transactions in that block are returned to the mempool.
  3. Stale blocks occur when the network decides which blockchain to continue. The protocol chooses the blockchain with the most proof of work.
  4. It is a best practice to wait for 6 block confirmations when sending or receiving a transaction because you never know if the block your transaction is on is going to get dropped and become stale.
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#3629

1. What happens in the bitcoin network when two miners solve a block at the same time?
They will both be added to the chain, but the one with the longest chain will survive. So the one connected to a new block first will be kept.

2.What is a stale block?
A stale block is a dropped block that is put back into the mempool, also known as an orphaned block.

3.How do stale blocks occur?
A stale block occurs when two blocks are added at the same time, one block will be dropped depending on which one is picked by a new miner to continue the block chain. The block not chosen will then be put back into the mempool.

4.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 to make sure that your transaction is really confirmed incase it becomes a stale block, give the blocks time to sync.

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#3630

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

  1. 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?

There temporarily will be 2 valid end blocks. After another block has been added, the longest chain will be confirmed.

  1. A discarded block of a temporary fork.

  2. Stale blocks these occur, if two miners simultaneously mine a block.

  3. To make sure the transaction was valid: transaction in stale blocks are returned to the mempool and are not yet valid.

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