Homework on Stale Blocks

[jelucamur]

1. What happens in the bitcoin network when two miners solve a block at the same time?
   There could be a problem in that different miners may choose alternative mined blocks and the blockchain then becomes forked. The miner who next completes a block will link to one of the forks thereby creating the longest chain and the redundant block will be discarded

2. What is a stale block?
   A stale block is the block described above that is discarded as it no longer forms part of the longest chain

3. How do stale blocks occur?

The blockchain takes too long to propogate to nodes providing the opportunity for 2 different miners to successfully mine a block and potentially create a fork
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

This is to avoid a transaction being rejected because it did not form part of the longest chain . Confirmation provides assurance that the transaction is in fact included in the blockchain

[Trinity]

1. What happens in the bitcoin network when two miners solve a block at the same time?
   There are two versions of the chain then. The one that is longer is being approved.

2. What is a stale block?
   That is a block that was created the same time with another one but wasn’t approved by the block after that.

3. How do stale blocks occur?
   When solving a nonce by two miners at the same time. The two blocks are true version for a while.

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
   For a confirmation is needed 6 blocks of time because that would be enough to elongate the true chain.

[BohemianJC]

1. When two miners solve a block in the bitcoin network at the same time the block in the longest chain wins and the other block is dropped this then becomes a stale or orphaned block and all the transactions then return to the mempool.

2. A stale block is a completely valid block that was in the blockchain but was dropped because another block which was produced at the same time had a longer blockchain. (longer blockchain wins)

3. Stale blocks occur when a two blocks are produced at the same time but one joins the blockchain and the other is dropped. The winning block joins the blockchain because it is part of the longer chain.

4. It is important to wait for more than one block to be confirmed preferably 6 because then you can be sure that your block won’t be dropped and will remain part of the longest chain.

[Diego_Sanin]

1. What happens in the bitcoin network when two miners solve a block at the same time? The block with the longest chain wins
2. What is a stale block?
   A block that was produced at the same time as another succesful block and is idscarted due to the absence of ussage
3. How do stale blocks occur?
   When two blocks are added at the same time to the blockchain but the next block is only added to one of the two the shorter one is then discarted
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? It is important to wait for 6 confirmations to make sure that the block the transaction is in is not discarted

[CeesQ]

@ivan

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

both blocks get appended to blockchain

@ivan

• What is a stale block?

a perfectly valid block that gets sent back to the mempool because a longer version of the blockchain now exists that doesn’t include the stale block

@ivan

How do stale blocks occur?

because the nonce of two blocks are solved by different miners at the same time

@ivan

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

to avoid the risk of your transaction being in a stale block (that gets sent back to the mempool)

[Wren]

1. When two miners solve a block at the same time, the nodes of each miner say that their miners blockchain is the only chain. One miners nodes do not know the other miner exists.
2. A stale block is a block that has dropped.
3. Stale blocks occur when a new miner joins with one of the two miners sharing the blockchain and is the one which the new miner did not connect.
4. It is important because the six confirmations ensure the safety of the transaction so it cannot become stale.

[Mercury]

1.What happens in the bitcoin network when two miners solve a block at the same time? - both blockchains are valid until one of them has a longer chain the other. The longest chain wins. The orphaned chain gets sent back to the mempool.
2.what is a stale block? - a stale block is a block that was once verified by a miner but later discarded because it was a part of a smaller blockchain.
3.how do stale blocks occur? - stale blocks belong to a verified chain. Once a larger verified chain comes along, the smaller chain is discarded.
4.why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? - waiting for atleast 6 blocks is recommended to make sure the transaction does not go stale.

[DFig]

they both begin propugating through the network until one is ultimately dropped

A stale block is a confirmed block that has less POW than a similar block mined at the same time

A stale block occurs when two blocks are mined at exactly the same time

Because if the block that contains your transaction, which contains one confirmation, becomes stail the transaction will be placed back into the menpool. Thus the transaction will revert to having zero confirmations.

[CryptoDD]

1. An additional miner will solve a block and add it too one of the 2 miners block and that will now become the blockchain of truth. The loser miners block will be removed and the transactions sent back to mempool.
2. A stale block is one that was rejected by the network and all transactions in that block returned to the mempool.
3. Stale blocks occur when the network does not adopt them into the blockchain.
4. It’s important so that the block can be confirmed by the network and in some cases a block can become a stale block and the transaction will be cancelled and sent back to mempool.

[Janine]

1. What happens in the bitcoin network when two miners solve a block at the same time?
   both blocks will be confirmed on the chain, but there will be 2 versions of the truth.

2. What is a stale block?
   A stale block is a block that has been accepted at first, but got dropped because it was not longer in the “longer chain”. the network only accepts the block with the most POW.

3. How do stale blocks occur?
   a stale block is a block that once was on the chain. once this block gets dropped, all the transaction within that block are put 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 to make sure that the block does not get dropped and become a stale / Orphan block.

[CryptoTube]

1. The blockchain will split into two different versions which will cause the shortest chain to be dropped and then will become a stale block and transactions will return to the mempool.
2. A stale block is a block that is rejected due to there being a longer version of the blockchain out there resulting in it having its transactions returned to the mempool.
3. They occur when miners mine a block at the same time causing half of all the nodes getting one version of the blockchain and the other half getting the other version and this results in only one version getting accepted causing one of the blocks becoming a stale block.
4. This reduces the chances of a stale block occurring.

[D3N1X]

1. It append to a blockchain but after six another block will be decided which block of these two will be part of blockchain.
2. Stale block or Orphaned block is that block which after six conformations will be dissolved and all transactions will appear again in mempool.
3. If two block are mined around same time and all network doesn’t have same block but one of two.
4. Because it could happened that someone can double spend or cancel transaction.

[HoS]

1. Both blocks get accepted by the nodes, but nodes will carry both versions of truth until the next block is generated.
2. A stale block is the block that is not linked to the next block generated.
3. It occur when the miner that mines the next block in line selects another block.
4. Because you want to make sure the blockchain is fully synchronized globally.

[Lane11]

1. What happens in the bitcoin network when two miners solve a block at the same time?
   Exp. we have a miner A and miner B that are producing a block at the same time. Then we are waiting for the 3rd miner and on which block of these 2 (A and B) miners the 3rd miner continue mine then that block of miner A or B will be accepted, depending which chain is longer. The longest chain always wins.
2. What is a stale block?
   Stale or Orphan block is a block that is returned from a blockchain in a mempool.
3. How do stale blocks occur?
   When 2 blocks were produced at the same time and then the longer chain wins, blocks which were in a shorter chain will be moved in a mempool and these block called Stale blocks.
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
   We need to wait for a 6 confirmations because of Orphan or stale blocks. Our block could be in a shorter chain and then will be moved in a mempool.

[kidsmoney]

1. They are added to block chain on different nodes
2. transactions in block that have been knocked off chain because chain to short and info sent back to menpool
3. new blocks not added to their chain fast enough
   4more cofindance your block is is on the longest chain.

[BryanSC]

1. When two miners solve a block at the same time, it will create a fork until the next miner chooses which block to build upon. The other block will be dropped and all transactions will return to the mempool.

2. A stale block is a block that has been dropped.

3. A stale block occurs when two blocks are solved at the same time, but then one is dropped because the blockchain was continued on another block.

4. It is important to wait for 6 confirmations to avoid your transactions being in a stale block.

[Aaron]

The two blocks are propagated and the chain with the future biggest PoW at the next block will be accepted.

2. The stale block is the block that is dropped from the chain that lost the PoW battle against the other chain.

3. When two miners mine at the same time AND the block in the losing chain is dropped.

4. To avoid your transaction from dropping and avoiding double spending if you’re receiving the funds that want to create this fraudulent transaction.

[claritacoin]

1. They will both go up and create two different blockchain, but depending on which block the next minor chooses which will then be the longest blockchain, the other block will then get dropped.
2. A stale block is block that has been dropped and does not belong to the blockchain anymore.
3. When to miners solve a block at the same time, they both go up on the blockchain. But only one block will get to stay depending on which will become the longest. The block that then belongs to the shortest blockchain will then become a stale block.
4. So the transactions doesn’t end up in a stale block

[Mercurydan]

1. there are two versions of the blockchain until the longest chain and highest POW difficulty wins
2. Are blocks that are dropped from the chain because there is a longer chain that won. Stale blocks are technically different to Orphaned blocks but people use them interchangeably
3. Stale Blocks are because there are several different versions of the blockchain depending on where the nodes are located and the speed at which miners mine a block. If the network chooses another chain over your nodes chain then the block becomes stale and returns to the mempool.
4. this is to make sure there is a high probability that your transaction will be on the blockchain. The more blocks that are mined the higher the probability your transaction is permanently on the blockchain as nodes start syncing from around the world. 6 blocks approx 1hr is the industry standard to be absolutely sure your transaction is immutable.

[Pkgno1]

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

Both blocks will be broadcast to the network, until another block is mined and added to one of the two blocks creating a longer chain and more proof of work. The other block is forgotton and dropped from the chain and all transactions in that block are returned to the mempool.

2. What is a stale block?

A stale block is the block that is forgotten and dropped from the chain.

3. How do stale blocks occur?

When two blocks are broadcast to the network at roughly the same time.

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

To make sure that your transaction wasn’t left in a stale block.