Homework on Stale Blocks

Blockchain and Bitcoin 101
#1544
  1. Network will create two different blockchains and eventually the longest one wins.
  2. Stale blocks (orphan blocks) are blocks that are dropped, cause they was in a shorter chain.
  3. When network has chosen the longest chain, 6 blocks after stale block have been mined.
  4. To make sure the transaction will be added to the valid chain.
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#1545
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    • The network will choose the version w/the longest PoW._
  2. What is a stale block?
    • Valid blocks that are dropped from the blockchain_
  3. How do stale blocks occur?
    • When miners produce blocks at relatively the same time, the one to propagate thru the network fastest w/the longest PoW will be accepted, causing the competing block to become "stale
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    • Wait for abt six block confirmations to ensure that the block ur trx is on does not become stale
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#1546
  1. The block is transmitted to the network and miners begin working on the block they received first.
  2. A block that is no longer valid
  3. When a longer chain is discovered
  4. That block could be a stale block
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#1547 
    1.What happens in the bitcoin network when two miners mine a block at the same time?

A 3rd miner is needed to create a longer chain. There is a 10min time limit to guess the nonce and verify transactions so it really depends on your ability to guess the nonce faster than the other miners.
2. What is a stale block?
A block that has been dropped and transactions returned to the mempool.
This is because a longer blockchain has been created within the 10min time limit, thus making it the verified chain.
3. How do stale blocks occur?
Because a longer blockchain has been created within the 10min time limit, thus making it the verified chain.
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
In order to prevent double spending. 6 confirmations is arbitrary. However, the more confirmations the less chance of the blocks being orphaned.

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#1548

  1. Both will be propagated through the network. As the process of mining continues, one of them will be dropped out depending on the one that gets new blocks faster.

  2. A valid block dropped out of the blockchain back to the mempool.

  3. When more than one block is added in the blockchain at the same time they will compete on which version propagate faster. When the nodes receive a longer version of the blockchain without the previously validated block it gets dropped out.

  4. It reduces the chances of being dropped out of the blockchain.

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#1549

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    – If 2 miners produce a block at the same time a fork will result each with 2 different yet valid versions of truth. Sooner or later another miner will produce a block and will add it to one of the forked chains possibly nearby node of the forked chain and that chain will be propagated throughout the network. Other miners may subsequently produce a block and add it to the other fork. One of the two forks will eventually have the longest blockchain in terms of POW and that one will win. The node(s) added to the losing fork will be deemed as stale block(s) and be dropped or orphaned from the network.

  2. What is a stale block?
    – A Stale block is a valid block that was added to a fork that is on a chain which is not the
    longest chain in terms of POW

  3. How do stale blocks occur?
    – A stale block occurs when 2 valid blocks are produced at the same time which causes the blockchain to fork and when one of the blocks ends up on a fork that is not the longest chain in terms of POW. Such blocks are deemed as stale blocks and orphaned from the network

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    – It’s best practice to wait for 6 more blocks to be confirmed because doing so allows enough time for the blocks to be propagated and to see if see the block your transaction is in will be seen as a stale block that has to be orphaned from the network.

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#1550
  • What happens in the bitcoin network when two miners solve a block at the same time?

only one block can be added to the blockchain. one block will be orphaned.

  • What is a stale block?

stale blocks are blocks that were on the blockchain at one point in time but is dropped from the chain because it lives on the shorter blockchain

  • How do stale blocks occur?

occurs when there are 2 competing blocks mined at the same time. one gets dropped

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

to ensure that transaction is broadcasted on the truest blockchain and not one that was orphaned.

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#1551
  1. The chain forms a fork into two valid ends.
  2. an orphaned block that is not longer accepted/confirmed
  3. When a block loses its source of truth and the opposite of the fork is appended.
  4. six confirmations are needed to avoid a stale block.
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#1552

1- both miners will be able to mine until another miner comes in to choose a block making the shorter chain invalid and returning that block to the mempool.

2- were blocks in blockchain is one time

3- when a third block chooses one block between 2 minors that solve the block at the same time.

4- to minimize stale blocks

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#1553

  1. What happens in the bitcoin network when two miners solve a block at the same time? - They both will be added to the blockchain but eventually one will win as the longest blockchain gets continued on it. The other block will be considered stale and will be dropped from the blockchain and the block goes back into the memepool.

  2. What is a stale block? - A block that is correct but introduced to the blockchain at the same time as another and gets dropped from the blockchain because the other block gets a longer blockchain continued on it.

  3. How do stale blocks occur? Two proof of work truths are introduced to the blockchain at the same time within the 10 minute interval of block creation. Nodes end up adding more blocks to one block and the other is dropped/orphaned because it is a shorter blockchain. Wait for 6 more blocks to come after a block is introduced at the same time to see which block gets dropped/orphaned/stale.

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? - To confirm if the block has been accepted. If the block is not on the longest blockchain after the block has been introduced to the blockchain i.e. 6 more blocks created, then it will become stale and the block goes back into the memepool. The blocks typically continue on the blockchain with the most proof of work/truth.

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#1554

Stale blocks will occur in either case, its kind of inevitable. Why is it important to wait from the perspective of the user that is trying to send or receive a tx? :slight_smile:

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#1555

Are you mixing blocks and transactions? The 6 confirmation time is basically just a rule of thumb at which point you can be quite certain your tx is not part of a stale block :slight_smile:

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#1556
  1. As long as they follow the rules both blocks will have stage 1 confirmation, then depending on which Txs are picked up in the few next blocks, this will determine what blocks are permanently added to the chain.
  2. A confirmed block that is no longer part of the longest chain, this gets dropped and it’s Txs are added back to the Mempool.
  3. They occur when miners achieve an acceptable target nonce at the same time, the system then needs to correct itself to have only 1 version of truth.
  4. It is important to ensure that your block is added to the main chain and not dropped back to mempool.
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#1557

  1. The chain temporarily forks, and the network must wait for the next block confirmation for consesus. The chain with the longest proof of work (POW) will be selected and the other rejected.

  2. A stale or orphaned block, is the blockchain block that was ‘not’ selected to have another block appended to it. This rejected block is sent back to the mempool.

  3. When 2 versions of the truth are produced at the same time. The version that gets propogated through the network first, having the longest POW, gets selected. The other, the shorter one is classed as ‘stale’ and gets dropped.

  4. The transaction may become stale and be rejected by the network. It is currently best practice to wait for at least 6 confirmations.

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#1558
  1. What happens in the bitcoin network when two miners solve a block at the same time?
    After some time one block will win by becoming longer chain of blocks while the other will be droped.
  2. What is a stale block?
    Block from which the chain did not continue.
  3. How do stale blocks occur?
    When blocks is appended to the chain but was abandoned cause the chain continued using another block which was appended 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?
    Because block can be abandoned and all transactions in that block can be sent to the mempool.
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#1559
  1. They both expect to continue the chain but there is only one winner and that is the longest chain (longest chain wins).
  2. When 2 miners mine the next block but the block with the shorter chain (orphaned block) is regarded as a stale block.
  3. Stale blocks occur when 2 miners mine the next block simultaneously, but one of the blocks don’t get confirmed into the blockchain.
  4. Because you transaction may be in a stale block.
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#1560

  1. When two miners solve a block at the same time (i.e. two different, but both valid blocks simultaneously) - then both valid blocks are propagated throughout the network to nearby nodes and both will exist until the next block is produced. The chain that the subsequent block is produced on is the chain that is then propagated and adopted throughout the network. This makes the previous “twin” block obsolete, and all of the transactions in it are added back to the mempool.

  2. A Stale Block is a block that was valid in the blockchain at one time, but ended up not being in the longest/greatest PoW chain and got dropped. A stale block is similar to an orphaned block.

  3. A stale block occurs when the shorter (/lower PoW) chain is abandoned by the miners and network nodes after two valid blocks were simultaneously mined.

  4. It is important to wait for more than one block when sending or receiving a transaction to ensure that your transaction is in the true/longest blockchain in existence.

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#1561

1 - Longest block will win because he has more PoW

2 - Stale block is a block that was confirmed onto the blockchain

3 - When some miners mine a block at the same time, the longest will win

4 - To no become an orphan or a stlale block

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#1562

Stale block was the block that was dropped from the blockchain :slight_smile:

Why is this important from the perspective of the user that creates or receives a transaction? :slight_smile:

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#1563

Because those transactions are returned to the mempool to be picked up in a future block

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