Homework on Stale Blocks

Blockchain and Bitcoin 101
#3250
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Longest and most widely accepted chain win.

  1. What is a stale block?

A block that was not accepted by the concensus.

  1. How do stale blocks occur?

When competing miners result in one miner’s block not being accepted as part of the chain.

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

More than one version of the chain may exist for several blocks before consensus can be established based on which version will be finalized.

1 Like
#3251

  1. If 2 miners solve a block at the same time, their respective blocks will propagate to the nearest nodes, creating a divergence of two valid blocks.

  2. A stale block is a block that was dropped ,because the other valid block was built upon first.

  3. Stale blocks happen when it’s twin is built upon first.

  4. If you wait for 6 block confirmations, you can be quite certain that your transaction is on the longest block chain.

1 Like
#3252

The tx is not lost its returned to the mempool, but gives an attacker the opportunity to double spend the UTXOs used in the tx. :slight_smile:

#3253

  1. one of them will win and the longest blockchain wins.

  2. It’s a block that was put on the side because the blockchain reach a point where at the end there’s 2 outcomes. The longest path is the one chosen.

  3. It’s when the blockchain splits into e path, the longest win and the other one becomes a stale block.

  4. Need to wait 10 min and have 6 confirmations to not get in a situation of many forks in the blockchain.

1 Like
#3254

  1. Both of the blocks are connected to the last block on the chain. The next block will link to one of them. The block that i part of the chain with the less POW will be dropped (orphaned) and the Tx’s returned to the mempool.

  2. Blocks that were dropped by the network because they eventually became part of a chain will less POW then the network blockchain.

1 Like
#3255
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Two blocks are added to the chain

  1. What is a stale block?

Its the name of a block that a miner has tried and failed to add to the network.

  1. How do stale blocks occur?

When a third miner comes along and picks one of the two found blocks and continues the chain. The loosing block gets dropped from the network as the chain progresses and becomes stale/orphaned

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

It allows for any stale blocks to be dropped from the network and released into the mempool to be picked up again.

1 Like
#3256
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    The block that has the longest chain will win , the other block will be dropped and all transactions are returned to the mempool.
  2. What is a stale block?
    A block that was mined correctly but got dropped because another block was validated at the same time and having a longer chain.
  3. How do stale blocks occur?
    When 2 miners mine a Block at the same time. (only 1 block can be confirmed)
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    Because block can always be rejected , the longest chain will always win. By waiting for 10 mins everything should be synced , validated and implemented in the blockchain for good.
1 Like
#3257

  1. If two miners solve a block at the same time then the one that has the most follow up blocks linked to it will win. The longer chain of blocks will be accepted and the other block that tried to get added will be added back to the mempool and be called a stale block.

  2. A stale block is a block that was added to the block chain and removed back to the mempool as a longer chain was produced on a block that was added at the same time.

  3. A stale block occurs when there are two versions of truth on the blockchain and the smaller chain is added back to the mempool as the larger chain contains more transactions.

  4. It is important to wait for more than one block to be confirmed when sending or receiving a transaction as the block could be turned into a stale block and your transaction made invalid. You should wait for 6 blocks before accepted the transaction is finalised and wont be made into a stale block.

1 Like
#3258

Thank you, that makes more sense!

#3259

  1. If two miners solve a block at the same time then both versions of the block are propagated through the network. Some nodes will receive one version and some will receive the other. Miners will attempt to solve the next block and depending on which of the blocks they received they will use its hash to add to their block structure. The miner that succeeds in solving this round will establish the previous block it used in its hash as the correct version of the blockchain as it is now the longest version of the blockchain.

  2. A stale block is the block that was solved at the same time as another but its hash was not used in the structure of the winning miner in the next round.

  3. A stale block occurs as a result of information having to be propagated across the network and can occur if there is a delay in syncing the network.

  4. It is important to wait for more than one confirmation, ideally six, when sending or receiving transactions in order to be sure your transaction was verified and is included on the longest blockchain. If it was only on a stale block it has returned to the mempool.

1 Like
#3260

  1. When two miners solve a block at the same time, there are two versions of truth so there is a temporary fork. the next miner to solve a block will only have one of this version of this (due to physical proximity) and then they will choose and the longest chain wins.

  2. A stale block is block with the shortest chain. It’s truth is not accepted by the chain and thus is cast back into the menpool.

  3. When their version of the truth is not accepted.

  4. To see which chain has been accepted. So transactions that are agreed upon are in the longest chain…

1 Like
#3261

  1. When two miners solve a block at the same time, the blockchain forks until the next block is mined. It is deterministic which block will be mined on based on what node the miner retrieves its transactions from in that moment.

  2. A stale block is the block that gets rejected from the blockchain and back to the mempool.

  3. A stale block occurs when the longest blockchain is verified.

  4. It’s important to wait for more than one block, traditionally six, to be confirmed when transacting because it takes time for the nodes to propagate the longest blockchain to every node in the network.

1 Like
#3262
  1. Both blocks get pushed to the network and whichever one is accepted and built on the quickest wins out and gets added to the blockchain.
  2. A block that is valid but doesn’t get propagated to the network quickly enough to become part of the longest chain.
  3. See previous.
  4. To allow time for network to sync and drop stale blocks.
1 Like
#3263
  1. Blocks are sent to closest Node causing a fork in the chain until the next miner builds on top of one of the previous blocks. The block that is not built on will be dropped.
  2. A block which is dropped from the chain even if valid
  3. By two valid blocks being created the network will move to one and continue building on it causing the other to be dropped
  4. To be sure it does not become stale. The more confirmations the longer the block, the network always moves to the longest block.
1 Like
#3264

Homework - Stale Blocks
Bitcoin Basics

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    • The blockchain will split

  2. What is a stale block?
    • A stale block, or orphaned block, is a valid block that ultimately gets dropped off of the blockchain.

  3. How do stale blocks occur?
    • Stale blocks occur when miners solve a block at the same time, splitting the blockchain. Once another block is added to one of the splits and the network realizes that there is a longer, more valid blockchain it will drop the other block and put all of the transactions and data 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?
    • This is important because you want to make sure that you are not going to be on a stale block which will be broken off of the blockchain, further delaying your transaction(s). You want to wait for at least 6 confirmed blocks in order to make sure that you are on the one and true blockchain.

1 Like
#3265
  1. Both blocks are added to the blockchain, creating a fork, and the nodes build upon it, ultimately the chain with the most POW will be universally accepted. The chain not accepted is forgotten about and the block that had been previously added at the same time becomes an orphaned/stale block … which means that all of the Txs in that block are returned to the mempool.
  2. Is a block that was added to the blockchain that ultimately does not get accepted; also known as an orphaned block.
  3. When two miners add a block to the blockchain at the same time and one ultimately is not accepted, resolving the fork.
  4. To be absolutely sure that your Tx has been confirmed and is appended to the blockchain, best to wait for 6 confirmations.
1 Like
#3266
  1. Both blocks can be valid, but they are competing with for the longest chain. Eventually the block on the shorter chain will be dropped. All tx will be returned to the mempool .
    2)A stale block is a block that has been dropped from the blockchain for a longer version.
    3)Stale blocks occur when two versions of the same chain are formed, once a point is reached to make a choice between the two chains the algorithm will select the chain with the most proof of work,
  2. So there is less of a chance the transaction being dropped
1 Like
#3267
  1. the block starts to propagate through the nodes creating 2 competing truths.
  2. A Stale block is a valid block that is ignored and returned to the mempool by the nodes because a competing block is part of a longer chain
  3. How do stale blocks occur? A Stale block is formed when a competing block has a new block added onto it creating a longer chain, the network always chooses the longer chain so the block that was added to what then becomes a shorter chain becomes stale.
  4. Your transaction is not confirmed until at least 6 blocks have been added to the chain to ensure that your transaction does not end up in a block that becomes Stale.
1 Like
#3268

  1. Both blocks will be valid until the network accepts the longest chain. and the transactions in the rejected block will be back to the mempool.

  2. Blocks which have been dropped, also known as orphaned blocks.

  3. Stale blocks refers to the block which gets rejected by the block chain as the competing block wins and becomes part of the longest chain.

  4. It is important as it takes 10 minutes to synch the network - if you wait for more than one block to be confirmed when sending and receiving you will minimize the chance that the transaction is part of and stale/orphaned block.

1 Like
#3269
  1. Both blocks are added to the blockchain forming a fork.
  2. When two blocks are formed at the same time and added to the block chain, the stale block is the one that is dropped by the network.
  3. When two miners solve a block at the same time, both blocks are added to the block chain forming a fork. When a subsequent block is solved it appends to the block with the closest node. This becomes the longer block chain, so it is confirmed and the last block of the shorter block chain becomes a stale block and is dropped.
  1. It is best to wait at least six confirmations to be assured that your block was retained in the block chain and did not become a stale block.
1 Like