Homework on Stale Blocks

1.) when to miners solve at the same time a block then it depends on the next block where comes. The network always chose the longest chain with PoW and the transactions from the other block comes back in the mempool.

2.) its the latest block on the shortest chain when miners solve a block at the same time.

3.) the transactions from the block goes back to the mempool and the miners start from the beginning.

4.) because it could be that your transaction is in a stale block.

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

The blockchain will split into two ends and begin propagating throughout the network. The block that forms the longest chain in the network will become the new addition, with the other block becoming a stale block. The transactions from the stale block will be returned to the mempool.

What is a stale block?

A stale block is the discarded block from the shorter version of the blockchain. The transactions from the stale block are returned to the mempool to be processed into a new block.

How do stale blocks occur?

When two miners amend a valid block into the blockchain at approximately the same time. These newly amended blocks propagate throughout the network until the longest chain is accepted, and the new block from the shorter chain is discarded. The transactions from this discarded block are returned to the mempool.

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

New blocks have a possibility to become stale blocks. It is standard practice to wait until 6 confirmations.

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  1. Both blocks will be added to the network, two different version of the blockchain will be propagated until the network choose one of them.
  2. Its a valid block that did not get linked to the blockchain, therefore the transcations get back to mempool
  3. This happens if 2 miner append their block to the network at the same time.
  4. So you can be sure the transaction is not a stale block, therefore wont get linked to the network and get dropped.
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  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The one which is built upon by another block (+1 or more) will create a longer chain and therefore the other block will fall off (become orphaned/stale)
  2. What is a stale block?
    A block that was rejected by the network and has fallen off the blockchain
  3. How do stale blocks occur?
    When 2 blocks are created at the same time and one of the two is built on by another block before the other.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because it can become a stale/orphaned block if it does not have multiple blocks created upon it, therefore confirming its validity, causing it to become “invalid”.
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  1. They will both be put on the network, but once the next block is mined the longer chain will be valid and the other block will be removed and all transactions from that block go back in the mempool.

  2. It’s a block that is removed from the blockchain after it was mined.

  3. When 2 miners mine a block at the exact same time. They both found a correct nonce at the same time.

  4. Because it can be on a stale block . The transaction would be on the blockchain but will be removed and send back to mempool once another chain would be validated. After 6 confirmations that is highly unlikely to happen.

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

Some nodes will receive one block while other nodes receive the other block. Usually determined by latency from the miner to the different nodes. Some nodes now have one “truth” and the other nodes another “truth” of the state of the network. Will be resolved when new blocks get added to one of the competing two versions of the block based on which version that miner was operating with.

  1. What is a stale block?

A stale block is a block that was valid, but that eventually got dropped because their was a competing block that became the longest chain.

  1. How do stale blocks occur?

See answer 1 . Occur when miners solve a block very close to each other in time.

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

So your transactions is not part of a block that becomes a stale block.

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  • What happens in the bitcoin network when two miners solve a block at the same time?
    1. Both miners will propagate their confirmed block with included transactions to nearby nodes, using geo-promixity.
  • What is a stale block?
    1. A block that has been orphaned because a longer chain has been created. A longer chain always trumpets all other chains including those blocks not found in the longer chain will be stale.
  • How do stale blocks occur?
    1. When a block is not part of the current longest block chain in circulation.
  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    1. Per the mathematical probability associated with the occurrence of more than one miner completing the puzzle, aka computing a hash with a numerical value below the target number, at roughly the same time.
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  1. When two miners solve a block at the same time the blocks will be broadcast to the network and the closest nodes to the miners will hold it as the truth. once an additional block is mined on one of the truths, that chosen chain will become the valid chain.

  2. A stale block is a block mined that was unsuccessfully mined on top op.

  3. Stale blocks occurs when 2 separate chains are created by two miners finding a valid nonce at the same time.

  4. Its important to wait for more than one block confirmation so that your transaction was not part of a stale block.

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  1. Two different version of blockchain will be propagated till the network has chosen one over the other.
  2. A stale block is the block that was in the blockchain but then dropped because another block that was produced at the same time was part of a longer chain.
  3. Due to 2 miners mining a block at the same time, one of both will go stale.
  4. To be sure your tansaction is accepted and not dropped due to stale block.
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  1. they are both recognized. however, the good practice is to wait for 10 min and 6 following confirmations in order to ensure the solved block is accepted by network.
  2. valid block that was didn’t get buy-in and thus was lost on the following iterations, sending it back to mempool instead of mass adoption of the network.
  3. 2 miners solve the block at the same time. one then gets used for following 6 iterations and thus gets adoption 1st. the other block is then ignored by the system and thus becomes stale.
  4. in order to ensure adoption of the solved block in the network system.
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  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Some nodes will accept one of the chains, some will accept the other. Then, some miners will choose to build on one chain or the other. Depending on which chain can add new blocks and become longer, that chain will be consider the source of truth. The other chain will be dropped and any transactions that havent been recorded will go back to the mempool.

  2. What is a stale block?
    a block that was part of a chain that was not then built-on with more blocks.

  3. How do stale blocks occur?

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To make sure that the transacation has propagated, and that the chain it was put on has grown, and therefore is the blockchain of truth

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9

  1. Thy gossip to the network of nodes, then nodes closest to miner pick up respective solutions. Network must wait for a confirmation to settle consensus. Finally, the longest chain wins.
  2. Stale block is a block that doesn’t get included into blockchain
  3. Stale block occur when two miners solve block at the same time then we have two versions of the truth, one has been invalidated (stale blocks)
  4. Because a newly added block can be invalidated
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1. What happens in the bitcoin network when two miners solve a block at the same time?
There will be two versions of the truth propagated on the network, some computers will see one version and the other will see another.

2. What is a stale block?
It is a block that was accepted but not used as a continuation of the blockchain due to a lag in the time of propagation. Also called orphan block. They will eventually be dropped and replaced by the accepted truth (the block that was accepted and confirmed).

3. How do stale blocks occur?
When one different version of the blockchain is confirmed by the next block and the stale block is not used/accepted as the truth by the whole network (lack confirmation/not used as part of the continuation of the blockchain).

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
Because a confirmation is necessary to guarantee that the block (including all of its transactions are permanently accepted as valid in the whole network).

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

Sooner or later one of this blocks will become an orphaned (stale) block and txs will go back in the mempool.

  • What is a stale block?

Is a block returned in mempool after it was included (and excluded) in actual chain.

  • How do stale blocks occur?

When two miners solve two or more blocks at the same time one part of participants accept one of this blocks and another part will accept another one. This can`t go long so after a while the longest one will stay in the chain and the shortest will go back into the mempool.

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

To ensure that you tx will not return into the mempool.

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  1. They both start propagating their new blocks to the nearest nodes. The next miner that mines a new block adds their version of the blockchain to the blockchain. The version(s) that the new block did not choose is dropped and put back into the mempool.

  2. A stale block is a block that is dropped and its transactions sent back to the mempool because there is a longer version of the blockchain on the network.

  3. Stale blocks occur when there are longer versions of the blockchain.

  4. It is important to wait for more than one block to be confirmed so that your block does not get dropped

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  1. Both get propagated through the network, where Nodes hear about them at potentially different times. Both can be accepted, but which one is ultimately established in the blockchain (see answer 4).

  2. A stale block is a block that is valid, but has not been accepted into the blockchain (see answer 3)

  3. Block A and B are both valid and ready to be accepted in the blockchain, but only one can proceed ultimately. When a miner comes along and establishes a new block on A for example, then block B becomes discarded and is considered a stale block.

  4. Because it’s only then that the transaction is fully set in stone. Before a couple and Ivan spoke of the example of 6 further blocks that there is no risk for ones transaction to be invalided or dismissed. The Blockchain always accepts the longest chain, whichever that would be is going to become part of the blockchain permanently. By the amount of transactions and miners that go on simultaneously, there is a good chance for multiple chains.

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What happens in the bitcoin network when two miners solve a block at the same time?
 R:. Two blocks are created are both are valid so we get a split on the chain. The longest chain will win.

What is a stale block?
 R:. After we get 2 valid blocks, the next blocks will decide wich "side" will be the main chain, the one that looses is called a stale block.

How do stale blocks occur?
 R:. when two blocks are created at the same time one of the side gets less blocks after it.

Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
R:. the chain needs to propragate and as we explainned earlier we sometimes get dropped blocks, so we won´t propragate those we wait 10 minutes. after that time we surely get a longer path.
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  1. When 2 miners solve a block at the same time the block in the longest chain wins and the other block is discarded and considered a stale or orphaned block. All the transactions are returned to the mempool.
  2. A stale block is the block that was in the blockchain but then dropped because another block that was produced at the same time was part of a longer chain.
  3. Stale blocks occur when a block was valid for a while because 2 were produced with the same version of the truth but then dropped because the blockchain continued on another block.
  4. It is important to wait for 6 confirmations to be sure that the block your transactions are in is not dropped from the chain.
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  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The miner in the longest block will win and the other dropped into a Mempool.

  2. What is a stale block?
    A stale or orphoned block is the block that was dropped when two miners solved a block at the same time.

  3. How do stale blocks occur?
    Stale blocks occur when the shortest block was dropped.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? To prevent you from entering into a stale block that would be dropped.

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1.1 block goes stale.
2.a block that has been dropped from the chain
3.it is not the longest chain
4.to make sure it is not a stale block

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