Homework on Stale Blocks

Blockchain and Bitcoin 101
#4454

1. What happens in the bitcoin network when two miners solve a block at the same time?
This creates two versions of the blockchain that begin propagating throughout the network. Eventually one of these two blockchains will become the official blockchain while the other produces stale blocks.

2. What is a stale block?
A stale block is a block of transactions that disregarded in favor of a longer blockchain that contains more POW.

3. How do stale blocks occur?
Stale blocks occur when two different miners add their blocks to the existing blockchain. This creates two versions of the blockchain. As the versions are propagated across the network eventually the version of the blockchain that contains more evidence of proof of work becomes the authoritative blockchain. The other chain drops the unconfirmed blocks and all the transactions are released 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?
Because the block that contains the transaction that I care about could be dropped and turned into a stale block. Best practice is to wait until there are 6 confirmed blocks after the block containing the transaction that I’m watching.

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#4455

  1. The next mined block will fix to one of them, and it is this one who will be the new blockchain (because the blockchain will be longer on this one). The other block will simply be refused and transactions in it will go back to the mempool.

  2. It is a block that has been rejected from the blockchain

  3. Because 2 blocks could be mined at the exact time. That’s why we have to next for the next minted block to confirm the “real” blockchain (10 minutes)

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#4456

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Both blocks will start propagating their block to the rest of the network. Other miners will start to work on the version of blockchain where they believe is the longest. Once another miner successfully hashes a new block, it will get added to the chain. The shorter chain will then get dropped and all miners will then shift to work on the longest chain.

  2. What is a stale block?
    Completely valid block that got dropped and put back to the mempool because the block was no longer in the longest chain.

  3. How do stale blocks occur?
    Two blocks got added to the blockchain roughly at the same time and one later becomes longer than the other. The last block in the shorter chain becomes stale block.

  4. 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 and became a stale block if it is no longer on the longest chain.

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#4457
  1. The blocks in the chain splits.
  2. The blocks in the chain splits on two and one of it is temporary.
  3. The stale block is the shortest unconfirmed branch.
  4. The necessary time to veryfy requiers certen amount of confirmation so it drops the branch line.
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#4458
  1. both blocks will be accepted. But the longest chain with the most difficult hashrate wins. After winning the shorter chain will be dropped.
  2. A previously accepted block but got dropped after losing from a longer chain on the blockchain.
  3. if 2 miners create a different block at the exact same time, one of them blocks will eventually become a stale (dropped) block.
  4. Because chances are there your transaction with only 1 confirmation becomes a stale block and gets sent back to the mempool.
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#4459

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The blocks will start propagating through the network, only one of these two blocks will win and stay in the blockchain. The winner will be the one that miners will use as a continuation of the blockchain by mining the next block, so the block in the longer chain will win, while the other one will be dropped.

  2. What is a stale block?
    Is a valid block that was temporarily in the chain, but has been dropped because another block, that was mined at the same time, was part of the longer chain and used in mining the next block. Transactions in the stale block will go back to the mempool.

  3. How do stale blocks occur?
    Stale blocks occur when two blocks are mined at the same time and only one can win the slot in the blockchain, so the other block is ignored, called stale or orphaned.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    It’s best to wait for 6 confirmations or more in order to make sure your transaction is not in a stale block that will be dropped and transaction will go back to the mempool.

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#4460
  1. When 2 blocks are solved at the same time the block with the longest chain wins and the other becomes an orphaned block and is dropped resulting in all transactions returning to the mempool.
  2. A stale block is a block that was once in the blockchain but now has been discarded because another block was produced at the same time, but that block 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 another block.
  4. It is important to wait for 6 confirmations just to be sure that the block containing your transactions is not dropped from the blockchain.
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#4462
  1. It is determined by the solving of the next block- with that next block being accepted and confirmed.
  2. A stale block is a block previously recognized by some nodes, but has been kicked back to the mempool for new confirmations due to the rule of “longest chain wins”.
  3. Once a “next block” is accepted for the chain- creating a longer chain for the “longest chain rule”- the previously accepted- by some nodes- blocks must be reprocessed to maintain block immutability.
  4. Due to this global chain needed to have an accepted truth being absolute, there must be no doubts or debates- as described above- or else an unwanted fork will occur.
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#4463

  1. Each miner propagates their block to the network, the network waits for confirmation to decide consensus(6 blocks confirmed after the initial block).

  2. A stale block is a legitimate block that gets discarded from the blockchain.

  3. When the network chooses one chain after an accidental fork, the transactions in the rejected chain are sent back to the mempool. The transactions that are sent back to the mempool are called stale blocks.

  4. To be sure that your transaction is not in a stale block.

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#4464 
1- What happens in the bitcoin network when two miners solve a block at the same time?

Both with add a block to the chain on their node. When the nodes are replicating through the network, other nodes will add valid blocks to the now two different blockchains. After some time (replications) the longest blockchain will win. The new blocks in the loosing blockhain will become stale blocks.

2- What is a stale block?

A stale block is a valid block that had been added to the blockhain, but was dropped  beacouse a longer blockchain on other nodes became truth. The transactions from the stale block are automatically transferred back to the mempool for further processing, so they do not get lost.

3- How do stale blocks occur?

Beaucse of network latency in the global network. Not alle nodes as in sync in realtime.

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

usually wait for 6 mor blocks (6 more confirmtions) to be sure, that the blocks will not be dropped because the chain had enough time to replicate ofer the network and is acceppted as the right (longest) blockchain
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#4465

1.) When two miners solve a block, simultaneously, a fork is created…two paths created. Ultimately, whichever path is extended first will win out. Because the network will favor the longest chain.

2.) A stale block (aka, an orphaned block) is a once confirmed block that got abandoned by the blockchain due to the extension of the chain ultimately continuing through another confirmed block.

3.) They occur when a choice is made to go with one confirmed block, over others, as the continuing path for the blockchain. The others become stale.

4.) You wait, just to give it a little time to ensure that your block doesn’t turn out to become orphaned.

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#4466
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Then there are 2 versions of the blockchain scattered through the network. The miner, who adds the next block is responsible for what block actually stays in the ledger and what block is discarded and the tx with it transfer back to the mempool. It depends on which version of the Blockchain this specific miner adopted, as the longer chain is accepted by the network.

  1. What is a stale block?

A stale block is a valid block accepted by the network that is discarded, due to another block, which was mined at the same time, being part of a longer chain. The tx list with it is transferred back to the mempool.

  1. How do stale blocks occur?

As said in 2. they occur when 2 blocks are mined at the same time. The block, which is not being used by the next miner to add the next block is discarded, due to the acceptance of the longer chain by the network. Consequently all tx in it are being transfered back to the mempool, waiting to be put into another block again.

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

To be sure the block containing your transaction is fully confirmed by all nodes and not dropped from the chain, due to there being a longer chain.

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#4467

  1. When two miners solve a block at the same time, the network will wait for a new miner to solve a new block and add it to either previous block, therefore creating a longer blockchain which will then be used to continue. The other block will then be dropped and its transactions will be sent back to the mempool.

  2. A Stale block is also known as an Orphaned block is what the dropped blocks are called.

  3. Stale blocks occur because the network always chooses the longest blockchain and therefore those blocks which are left out become stale or are dropped.

  4. It is important to wait for more than one block to be confirmed when sending or receiving a transaction (Best practice is 6 blocks) in order to make sure your block has not been dropped.

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#4468

  1. They usually wait for the 10min rule to see if one block gets extra nodes and adopt that as the truth therefore rendering the other chain stale.

  2. A stale block is one that was not adopted as the final true block.

  3. They occur when two chains build up same number of nodes at the same time but are not adopted as the final true chain.

  4. It is very important to ensure that the chain with the most block is adopted otherwise some nodes might hang onto stale blocks.

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#4469
  1. The miner that solves its block and has the longest blockchain wins and therefore the other miner’s block gets dropped and returned to the mempool
  2. Stale blocks are blocks that were in the blockchain at one time but got dropped.
  3. Its occurs when two miners mine a block at the same time and the block that gets dropped is a stale block.
  4. To be sure that the block with your transaction has been confirmed and has not been dropped. Anything after 6 confirmations is recommended.
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#4470

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Both valid blocks get added to the blockchain, the chain is split. Then other miners add blocks to either of those chains. The chain that gets longer faster is the one that will stay and the other chain is dropped and its transactions go back to the mempool.

  2. What is a stale block? / 3. How do stale blocks occur?
    Block which was successfully mined and thus added to the blockchain but which gets back into the mempool because some other block at the same height had its chain extended first.

  3. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    A transaction is only confirmed when six more blocks come after the confirmed block are confirmed because the block might be in a chain with blocks gets dropped back into the mempool. This is to minimize the issue with stale blocks

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#4471

  1. The surrounding nodes of each respective miners will confirm the existence of the new block, essentially creating two different “truths” with both resultant blockchains continuing. In this case, a third miner will create a new block on whichever of the two blockchains it chances upon, making this the confirmed chain moving forward. This is because as a rule, the protocol will accept the longest/most complex blockchain as truth. The blockchain that is not chosen will drop its block, and this block will be removed from the network.

  2. Stale blocks are the blocks that are removed from the network due to succeeding blocks being built on a “preferred” blockchain during the rare event of double block creation.

  3. See above :wink:

  4. Absolute confirmation is achieved when there are six successive blocks created after any given transaction’s block has been appded. This is because of the above possibility of two different blockchains existing at the same time. Transactions on stale blocks are returned to the mempool and are not considered “set in stone”, so in order to be absolutely sure of the validity of your transaction, you must wait for more than at least one block to be confirmed.

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#4472
  1. 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.
  2. blocks that are not accepted into the blockchain network due to a time lag in the reporting of the block
  3. As multiple, competing chains get blocks added to them, they increase in length, all competing to become the longest. During this contest, some blocks on a shorter chain can get left behind, creating stale blocks.
  4. In case of a stale block occurring.
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#4473

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    Some miners will continue mining on top of one block and some on top of the other. Eventually one of them will get a subsequent block, becoming the longest chain, and the other one will go stale.

  2. What is a stale block?
    A stale block is a valid block that was dropped due to another strand of the blockchain having become the longest one.

  3. How do stale blocks occur?
    Stale blocks occur when multiple valid blocks are resolved at the same level due to network propagation delays, resulting the network being temporarily split into multiple competing states. As the network eventually reaches a consensus, one state is selected and the others become stale.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because there is a risk of the block going stale, and the risk goes down with every confirmation.

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#4474
  1. Both blocks will spread across the network and miners will add one of the two copies to their ledger. Two versions of the blockchain will temporarily exist until a longer chain with the most accumulated computational work overrides the lesser block.
  2. Successfully mined blocks that are dropped from the network and overridden by a longer chain.
    3.When two miners produce blocks at the same time, one must be dropped from the chain resulting in a stale block.
  3. The opportunity for a stale block may occur and all transactions within that block will be sent back to the mempool.
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