Homework on Stale Blocks

Blockchain and Bitcoin 101
#1604
  1. The miner with the longest blockchain and most confirmations on the blockchain wins the incentive.
    2.A stale block was a block that was accepted in the block chain but, another miner gave a longer chain so the original block gets discarded.
    3.Stale blocks occur right after two separate miners mine the same block at the same time, basically free for all.
    4.It is important to keep different blocks confirmed more than once simply as a block becomes more stable to stray from being a stale block
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#1605

Why is this practice important from the user perspective? :slight_smile:

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#1606

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Initially 2 parallel branches form with part of the network recognising one block (say block K) and part of the network recognising the other (say block L) as forming the valid chain. The next block to be mined (say block M) determines which version of the chain is adopted by the network (longest chain being the correct chain); if block M is mined after block K then the valid chain becomes …J-K-M and block L is dropped however if it is mined after block L then the valid chain becomes …J-L-M and block K is dropped. The content of the dropped (or “stale”) block are returned to the mempool

  2. What is a stale block?
    a stale block is one which was mined in a valid way but dropped from the chain due to another block being produced at the same time.

  3. How do stale blocks occur?
    See 1 & 2

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    transactions included in a stale block are initially confirmed but when the block content returns to the mempool the transactions again become unconfirmed (and possibly therefore retractable)

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#1607
  1. The both blocks are accepted by the network and become two versions of the truth. After some one of them becomes stale block.
  2. Stale block is block transferred to mempool.
  3. Stale blocks occurs when two miners solve a block at the same time but latter when another block is added to the network, the network accept the larger chain (in term PoW) so inevitably one of the blocks (the one not being accepted) become stale block.
  4. It is important to wait 6 confirmed transaction (6 blocks) to assure that transaction is going to be accepted.
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#1608

  1. The block that is used in the chain is the one that precedes the next block mined.

  2. A block that was not used and transactions put back into the mempool

  3. When two blocks are mined at the same time and chain uses the other block

  4. To make sure that your transaction was included in the mined block and not a stale block

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#1609
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    • Some nodes will receive info from one block and the other nodes will receive info from the other block. The block that has the longest chain will be valid, while the other will become a stall block.
  2. What is a stale block?
    • A stall block is a block that was one on the blockchain but was dropped off because another block was part of a long blockchain than the other block.
  3. How do stale blocks occur?
    • They can occur when two miners sole a problem at the same time
    • When new blocks are being added to the network at such a pace that the system can’t keep up.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    To confirm that the block isn’t stale block and that the block is accepted into the blockchain.
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#1610

1.if 2 miners find a proof at the same time,then both will broadcast the proof at the same time.some nodes will recieve block A first while other nodes will receive the block B first . those miners who receive block A first will start working to build the next block on top of block A

2.orphan blocks, often referred to as stale blocks, are blocks that are accepted into the blockchain network due to a time lag in the acceptance of the block in question into the blockchain, as compared to other qualifying block. orphan blocks are valid and verefied blocks but have been rejected by chain.

3.stale blocks are generated when 2 different miners relay the their valid blocks almost at the same time. this causes the network to split into 2 competing versions of the blockchain until one of the blocks is discarded (the longest chain prevails while the other is abandoned.)

4.becase it can possibly become state if theres multiple versions of the truth . 6 confirmations is recommended.

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#1611

1- Both of the blocks can be validated but only one block will be continued and attached to more blocks.
2- Blocks that were in the Blockchain one time and then got drop.
3- When the chain is not continued by more blocks.
4- When two chains are added into the blockchain its better to wait 6 confirmations that the block isn’t getting drop.

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#1612

1)It will be added to the blockchain. Then this will cause nodes to receive two different truth of block.
2)A state block is when a valid block in the blockchain got drop out because there is another longer blockchain version.
3)To minimize the cause the stale blocks. Wait for 6 confirmation is the best

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#1613

  1. Both blocks will be propagated through the network until one of them is dropped because the other once is part of the longer chain.

  2. Stale block is a block which was mined and propagated through the network but was dropped in the end.

  3. Stale block occur when 2 blocks are mined at the exact same time and both start propagating through the network.

  4. So that to make sure your block/transaction is 100% through and no chance of it being dropped later.

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#1614

  • What happens in the bitcoin network when two miners solve a block at the same time?
    Both blocks are taken by the nodes nearest to them but since there cannot be a split blockchain, the longest block with the most proof of work is accepted and the other one is dropped out,.

  • What is a stale block?
    It is a valid block that is dropped out of the network because of another competing block.

  • How do stale blocks occur?
    There can only be one version of truth on the blockchain, so if more blocks with the same version are simultaneously produced only one can be appended and the others have to be dropped.

  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because your transaction can be verified by a node but end up not being confirmed by the blockchain because it is stale…

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#1615

Loved your first answer. It’s easy to understand. Great work. :clap:

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#1616

  1. Both blocks will be appended to the blockchain and propagated to local nodes and eventually throughout the entire network. During this time, each version of the blockchain could have other new blocks appended, leading to two versions of the truth. The network will always choose the longest blockchain as the truth, however, so the blocks in the shorter blockchain will be dropped and all of the transactions contained within those blocks will be invalidated and returned to the mempool.

  2. A stale block (also sometimes called an orphan block) is a block that was in the blockchain at one point but was subsequently dropped from the blockchain.

  3. Stale blocks result from the situation described in answer number 1 above.

  4. When sending or receiving a transaction, it is prudent to wait for more than one block to be confirmed (ideally 6 blocks) to give enough time to ensure that the block your transaction was in was, indeed, included in the latest version of truth and did not end up in a stale/orphaned block.

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#1617

  1. Whichever miner has completed the most blocks will be the one chosen to have its updated version propagated through the network.

  2. & 3 A stale block is one of the block that was not picked up by the final copy of the blockchain. That miner did not have the most blocks completed so therefore these blocks were dropped.

  3. Because your transaction could be written in a block that will get dropped. So you need to have at least 6 confirmations in order to avoid this.

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#1618
  1. The nodes closest to the two miners will record each chain until the next fastest block is mined. Once a new block is mined, it will be appended to one of the two chains. Whichever chain receives the new block will be longer and accepted as true by the network. The other block will be invalidated and return to the mempool until it is mined again.
  2. A stale, or orphaned, block is a block that was not confirmed onto the chain.
  3. They occur when two miners mine a block at the same time, but only one can be accepted as true on the network. Whichever chain mines the next block fastest is the block that is validated on the chain that holds that block and the slower block is the stale block on the discarded chain that existed temporarily along side the chain that was validated.
  4. To ensure there are no stale blocks in the network.
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#1619
  1. Whichever block the next miner picks will be the official block that is added to the network and the unpicked block will be dropped.
  2. Blocks that are produced too quickly.
  3. When a block is produced before the ten-minute network propagating window.
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#1620
  • What happens in the bitcoin network when two miners solve a block at the same time? these two block needs to compete in solving the puzzle and whoever solves it first is able to save the transaction into the block chain and have the transaction propagated to the rest of the blocks.
  • What is a stale block? a stale block is when block gets back to the mempool
  • How do stale blocks occur? the stale blocks occur when another competing block had solved the cryptographic puzzle, the losing block is ignored and put back to the mempool.
  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? this is to get the consensus on a global chain of blocks to agree on the transaction.

I have a question –
What do you think might have caused this $5M ETH hack? is it due to some staled blocks or a glitch during the confirmation of the transactions?? appreciate any thoughts… thanks!

I recently stumbled upon this article over the internet:

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#1621
  1. What happens in the bitcoin network when two miners solve a block at the same time?

They both get their block in the blockchain – two versions of the truth. However, this will not last for long, explanation follows…

  1. What is a stale block?

It is a block that were in the network at some time, however, it god dropped, and its notes went back to the mempool.

  1. How do stale blocks occur?

Two blocks gets mined at the same time, one block “wins” the spot in the network. “wins” by having the longest chain due to the next miner chose this block, and therefore making the other block Stale. The longest chain always wins

  1. 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 transaction, is in a block, that actually get accepted to the blockchain by being part of the “winning” block

#1622

A node can’t accept both chains. It will accept the block/chain that first arrived at him.

A stale block was once a confirmed and valid block but is no longer part of the blockchain.

Stale blocks will always occur. We want to sure that our transaction wasn’t in a stale block.

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#1623

Stale blocks occur when the blocks are mined at the same time. While it’s more likely for it to happen when mining is faster, it’s not how they are produced.

Why do should we wait for six block confirmations?

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