Homework on Stale Blocks

Blockchain and Bitcoin 101
#4314
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Answer: 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. What is a stale block?
    Answer: A stale block is a block that was disregarded - resulting in all valid transactions being returned back to the mempool.
  3. How do stale blocks occur?
    Answer: The were previously valid blocks but as miners choose to add their block to a chain eventually only the longest chain of blocks is getting accepted by the node and the blocks on the other chain are getting dropped ie become stale blocks.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Answer: Because there is the chance that the chain with your block will be eventually dropped . That why it is best practise to wait for 6 x confirmations
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#4315
  1. Two separate blocks will form creating a split(fork).
  2. A stale block is the result of being the shortest between a set of split blocks.
  3. Stale blocks occur when they are the lesser of two validated blocks.
  4. 10 minutes insures your current transaction is not a stale block, or 6 blocks.
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#4316

1.The chain splits into two chains. The longest chain followed by miners will win, the transactions of the other chain will be returned to the mempool.

2.A stale block is a dropped blocked from the shortest chain from a fork, which will be not validated/confirmed as the accepted blockchain, all transactions in it will be returned to the mempool

  1. A stale block occurs when there is confirmation that its chain is no more part of the validated block chain or the longest chain.

  2. it is important to wait for 6 confirmations to be sure that the block with your transactions will not be returned to the mempool.

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#4317

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

If two miners solve a block at the same time then the longest blockchain will be considered by the network and the other one will be orphaned. This will happen within the 10 minutes block time frame.

What is a stale block?

If between competing miners, any blockchain is longest then from the other blockchains the block will be simply discarded and send it to the mempool. This block is called the Stale block or orphaned block.

How do stale blocks occur?

When multiple miners compete for the same goal of adding block to the blockchain, and if they solve the puzzle at the same time then the minimum number of 6 confirmations the longest blockchain will be added to the blockchain. The others will be removed and send to the mempool. These blocks are called stale blocks.

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

Minimum of 6 confirmations are needed when adding blocks to the blockchain and confirmed it. The reason behind more than one block to be confirmed is needed because, there could be multiple miners can solve the cryptographic puzzle at the same time or guessing the nonce at the same time. So to remove the friction between miners, minimum of 6 confirmations are needed, at this point there will be one winning longest blockchain evolved that will be confirmed and added to the blockchain as the winning blockchain.

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#4318
  1. The miners fight over the block chain, one will have half the nodes, the other miner will have the other half of the nodes circulating on the chain. Eventually one miner will win and the other miner will have a stale block.

2.Blocks that were circulated on the blockchain but got dropped.

  1. This happens when a block is on the chain but there was 6 confirmations on another chain which will drop the ā€œstaleā€ block.

  2. There could be a case when your transaction is in the block that will be dropped.

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#4319
  1. What happens in the bitcoin network when two miners solve a block at the same time?
  • The nodes in the bitcoin network will not have the same copy of the blockchain. Every node will have the block appended in the blockchain from either of the two miners. However, eventually the bitcoin network chooses and maintains the longest chain (more complex one in terms of PoW) as the single version of truth.
  1. What is a stale block?
  • A block that is dropped from the blockchain after the bitcoin network deems a longer version (more PoW) of the blockchain as the valid one.
  1. How do stale blocks occur?
  • If blocks are mined at the same time or blocks are mined so fast between each other and the propagation of the information of a newly mined block havenā€™t reach all the nodes in the network.
  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
  • Giving time for the information of a newly mined block to be propagated to the whole network; minimize the possibility to producing stale blocks; eliminating 2 or more versions of the blockchain competing with each other.
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#4320
  1. When two miners solve the a block at the same time. Both blocks will be propagated throughout the nodes and be appended to the nodes current state of the blockchain.
  2. A stale block is a block that has been mined and has been left out of the blockchain.
  3. Stale blocks occur when there is a conflict of miners both finding the a hash of the current block less than the target. One of the miners block is propagated through the network due to the largest POW of their version of the blockchain. The other block has been discontinued from the blockchain and all transactions have been returned to the mempool.
  4. Waiting for more than one block to be confirmed will guarantee the transaction will not be part of an orphan or stale block.
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#4321
  1. What happens in the bitcoin network when two miners solve a block at the same time? Two chains are temporarily created until the longest chain is confirmed and the block not on the longest chain is dropped.
  2. What is a stale block? A stale block is one that was created simultaneous to another block that ends up on the longer chain, and the stale block gets dropped.
  3. How do stale blocks occur? Stale blocks occur when two miners simultaneously confirm blocks, creating two different versions of the chain. When the longest and most difficult is ultimately chosen, the one not chosen gets dropped and that block is considered stale or orphaned.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? To confirm that your block wasnā€™t a stale block that ends up being dropped from the chain.
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#4322

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    an accidental chain split can occur until one is selected as true blockchain. once this occurs, the losing chain returns TX back to mem pool.

  2. What is a stale block?

stale block is a perfectly good block which was rejected from the main chain after the fact, due to a competing blockā€™s (same block height) propagation through the network winning out.

  1. How do stale blocks occur?

a competing blockā€™s (same block height) propagation through the network was adopted & integrated within the main chain as opposed to the stale block.

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

in case of stale block causing transaction reversion.

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#4323

  1. Stale block is a completed block that were existed in the blockchain but then got dropped and return to the mempools

  2. Stale block occurs when there are a longer block appear and the network accepted the longer block by dropping the shorter one (the stale block)

  3. Because a longer block might appear while your transaction are in the shorter block which might get dropped/become the stale block

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#4324

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Two blocks are are created. When the next block is created on one of the previously two blocks it will move the other block (stale block) into the mempool.

  2. What is a stale block?
    A stale/orphan block is when 2 blocks are mined and split on the chain. The block not chosen is drooped and is considered stale.

  3. How do stale blocks occur?
    Stale block occur when two blocks are confirmed at the same time.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    It give the network time to deal with the stale blocks. In 10 min everything should be confirmed.

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#4325

1.two versions of the truth are created but one block will be rejected depending on which block the next miner attaches their block to the rejected blocks transactions and fees will be sent back to the mempool.

2.a block that has been rejected due to the other version of the blockchain being longer.

3.a stale block occurs when two valid blocks are created at the same time one of these blocks will be rejected when the next block is added to the other chain making it longer and now the true version of the blockchain.

4.so you give enough time for the nodes to spread and update the correct version of the blockchain six confirmations equals confirmed.

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#4326

The best-case scenario is to wait for 6 confirmations to make sure your block is not state block.

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#4327

  1. Two miners solving a block at the same time is rare and thatā€™s why the difficulty level is put in place. Incases where this happens, a fork forms, basically 2 tails from a longer tail forms. The tail that is able to confirm the txns faster than the other tail wins by adding more blocks to that particular tail. The longest tail survives and continues to add more blocks to it.

  2. Blocks that are abandoned or collapsed and returned to the mempool are stale blocks.

  3. When BC propagation is slower/faster between nodes in different geographical locations, this can either cause a delay/quick in forming a new blocks. This can result in abandoning blocks when a new chain is formed.

  4. There is a chance that the block containing your transaction might not get propagated within the network as expected, which can turn out to be a stale block. So, its always good to wait till 6 confirmations before initiating a new txn.

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#4328
  1. The chain will split into two valid chains, however, the longest chain will win as the transactions of the shorter chain will be placed back into the mempool.
  2. A stale block is one that has been superseded by a competing miners block, whose block was accepted.
  3. when the new block has been propagated through the network at the same time of another one, without knowing that another one exists.
  4. Because in the case that two miners find a block at the same time, that will cause a blockchain to split into two blockchains and the next miner to find the next block will choose which blockchain to use to add his block.
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#4329
  1. when 2 miners solve a block at the same time both blocks will be confirmed initially.
  2. as in 1. above which resutlts in one blockchain being longer. the other chain thats shorter will be dropped or orphaned. Orphaned blocks are also called Stale blocks.
  3. the above answer in 2. also answers this question.
  4. a block time of about 10 minutes is required for atleast 6 blocks to be added to the blockchain only then a transaction is said to be confirmed.
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#4330

  1. It can produce a ramification of blocks that could end in the creation of two different hash in which the one with more blocks added to it would prevail and form the confirmed blockchain.

  2. A stale/orphaned block is an unconfirmed block that doesnā€™t follow the prevalent sequence on the blockchain, therefore, it canā€™t create a consistent sequence and is discarded by the network.

  3. When the network recognizes a slate block, it cancels this block from the chain before the formation of six new blocks linked to this unconfirmed ramification.

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#4331

  1. It creates two separate blocks which are both versions of the truth that additional blocks can append to. The miners and nodes will continue to build off of both sides of the forked block creating more blocks until one chain becomes longer. The network chooses the fork that eventually has the longest chain of blocks, allocating the transactions of the shorter block back to a mempool.

  2. Stale blocks a series of blocks that were formed from a shorter fork in the blockchain that become invalidated because a longer fork was chosen.

  3. Stale blocks occur when a longer chain of forked blocks is chosen by the network rendering the smaller chain an invalid version of truth. The blocks created where the fork occurred would all be considered stale blocks.

  4. The transaction you might have received might be part of a forked blockchain that the network hasnā€™t determined which chain is valid yet. If the chain the transaction was part of is considered invalid the transaction would have to be re confirmed therefore the network hasnā€™t actually completed the transaction.

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#4332

1- when 2 miners solve a block at the same time you create a fork in the chain with two valid ends
2- a stale block is a valid block in the chain fork that no longer makes part of the longer chain.
3- when you have to 2 blocks with the same version of truth, only 1 can remain in the chain. the Stale block is the one that doesnā€™t remain in the chain.
2- to make sure that in case of a fork situation the stale blocks return to mempool and your transaction block its connected to the chain.

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#4333
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Each block is mined & create a branch of the blockchain.
  2. What is a stale block?
    The block that was mined but left behind is a stale block, no longer apart of the blockchain.
  3. How do stale blocks occur?
    **When two miners solve a block at the same time, some miners will accept one version of the truth or the other & continue attempting to solve the following block. The next block that is mined is added to the previous block it believed to be the truth & the rest of the network will eventually accept this chain because the network favors the longest chain.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Itā€™s necessary to wait for more than one block to be confirmed to be sure that the block containing your transaction isnā€™t apart of a stale block.
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