Homework on Bitcoin Ecosystem - Questions

Blockchain and Bitcoin 101
#1687

  1. What is the difference between a SPV (simplified payment verification) and a full node?
    The SPV’s don’t store a full version of the blockchain, in turn they have to query a full node to know how many UTXO’s of for whatever information they wish to know. However, the full nodes stores a full version of the blockchain which is several GB’s and also stores their own list of unverified transanctions, which is called the MEMPOOL

  2. What does it mean when a transaction is broadcasted?

It means that the transaction is passed on to the neighboring nodes of the network until they reach every node in the network

  1. How does a miner pick which transactions that gets added to the next block?

The miner should try to find a balance between the fees that he should get (each Tx has a fee associated with it) nad the probability that his new block will be appended to the blockchain, in terms of the new block PoW value. It means that if one miner just tries to put one Tx in his block, so that he just receives the mining Fee (i dont remember how it is called) + this one Tx fee, the new block will probably be dismissed by other versions of the blockchain, becuase they have higher PoW.

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#1688

  1. SPV is a node without a copy of the blockchain, it depends on a full node for full information about the blockchain from a full node. And a full node is a node on the network that has its copy of the blockchain, it needs not contact or communicate with any node for information.

  2. A transaction is broadcasted in order to update all other nodes in the blockchain

3)Because the miners are incentive, they pick transactions based on fee

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#1689

When a tx is mined into a block it is considered confirmed. The blocks verify txs as the receive them from other nodes and store them in the mempool :slight_smile:

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#1690

The number of transactions in a block doesn’t effect the PoW, this is dictated by the target difficulty and there have been examples in the past that some mining pools were mining empty blocks (with the coinbase tx of course), this is not really effective since you don’t also get the tx fees associated with transactions that could be put in a block and its also an annoyance to the network since it resolves to congestion by tx not getting through, so I’m not sure why they did it.
Other miners of course saw this block as valid and continued to mine new blocks on top of it.

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#1691

  • What is the difference between a SPV (simplified payment verification) and a full node?
    SPVs are like partial versions of the full node as they contain partial listings of the transactions but also “receive” new transactions verified from the mempool by miners.

  • What does it mean when a transaction is broadcasted?
    Transaction has been verified and will be taken in by the nodes as valid

  • How does a miner pick which transactions that gets added to the next block?
    The higher the fee, the more likely it is for the miner to pick it up (as an incentive)

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#1692

  1. Full nodes store the whole blockchain while SPVs mostly store transactions relevant to its addresses and it requires a full node to send transactions.

  2. It propagates the transaction to all the nodes.

  3. A miner picks transaction from the mempool and pick the transcation with higher fee

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#1693

*SPV doesn’t require you to see every transaction in order to verify your transaction. Whereas, a full node does.
*Wallets broadcast transactions to be picked up by mining nodes on the blockchain network.
*The miner picks the longest chain and does it faster than the other miners. Then is rewarded in btc.

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#1694

  1. What is the difference between a SPV (simplified payment verification) and a full node?
    An SPV needs to connect to a full node to get information, as it doesn’t have a local copy of the full blockchain. Some wallets are like SPV’s. A node has a local copy of the entire blockchain.

  2. What does it mean when a transaction is broadcasted? When a transaction is broadcasted it is propagated across the entire network of nodes to be confirmed.

  3. How does a miner pick which transactions that gets added to the next block? Miners pick transactions based on the fee.

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#1695

the spv will be used more for mobile phone which does not have the full broadcasted blockchain. it will have to connect to a node which has the full blockchain info. the node is used mostly on computers that is directly linked to the blockchain network.

a transaction being broadcasted means it is being shared throughout the ledger network and lets people that is in the network aware of that transaction.

the miner picks the transaction that goes to the next block by choosing the one that has the highest transaction fee on the mempool.

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#1696 
What is the difference between a SPV (simplified payment verification) and a full node?

What does it mean when a transaction is broadcasted?

How does a miner pick which transactions that gets added to the next block?

  1. The difference between an SPV and a Full node is that a full node has entire copy of the blockcain. An SPV doesnt enough memory to store a copy of the blockchain and must query data from full nodes to broadcast transactions.

  2. When a transaction is broadcasted, it means that a transaction has been created by a wallet and sent to a node to be validated and further confirmed by a miner.

  3. Miners are incentivized through reward blocks and transaction fees. With that said, miners will choose to verify and confirm the transactions with the highest transaction fees first before the rest.

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#1697

  1. SPV is where it validate that the transaction is valid through a full node, and full node is the one that has the entire blockchain ledger.

  2. It means the transaction is valid, it is propagated to the network and is ready to be pick up and mine by the miner.

  3. They will prefer the transactions that has a higher fee as it will be prioritise.

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#1698
  1. The full node have a complete copy of the blockchain. The SPV looks on a full node when a transaction come in.
  2. Every node in the network have your transaction syncronized.
  3. Miners allways look for transactions with the highest fees and the lowest number of UTXO’s per transaction to save bytes.
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#1699

1.Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
a SPV doesn’t access to the whole blockchain, it is in connection with near full nodes to check the blockchain.
2.What does it mean when a transaction is broadcasted?
the nodes will verify the tx and if it is valid they propagate it through the network to update the mempools.

3.How does a miner pick which transactions that gets added to the next block?
by checking its own mempool or of other nodes, chooses the highest tx fee.

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#1700
  1. An SPV gets their version of the blockchain from a full node instead of having their own version.
  2. When a transaction is broadcasted it means it is being sent to all the other nodes and miner on the blockchain.
  3. A miner takes tx’s from the mempool and will usually pick ones with the highest fee (sat/byte) because they wanna get paid!
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#1701
  1. An SPV just has the capacity to read the blockchain for utxos, and broadcast TXs.
  2. It is in the mempool waiting to be confirmed into the blockchain.
    3.By choosing the transactions that pay the most from TX fees and Hash rate payout
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#1702
  • What is the difference between a SPV (simplified payment verification) and a full node?
    The SPV doesnt have a full copy of the blockchain it needs to connect to get this data in order to verify a transaction
  • What does it mean when a transaction is broadcasted? it means that it is transferred to all nodes in the vicinity from where it will propagate further.
  • How does a miner pick which transactions that gets added to the next block?
    Usually the transactions with the highest transaction fee in the mempool are chosen
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#1703

What do you mean by hashrate payout?

#1704

1- spv can only query the information from the node which has full copy of the blockchain.
2- all the nodes got an updated copy of the Blockchain
3- miner pick the most incentive transaction in the fees

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#1705
  1. What is the difference between a SPV (simplified payment verification) and a full node?
    A SPV only has portion of the Blockchain. A full node has the complete copy of the Blockchain.
  2. What does it mean when a transaction is broadcasted?
    It is sent to all the nodes around it to so it can be propagated further.
  3. How does a miner pick which transactions that gets added to the next block?
    By picking the transactions from the mempool with the highest fees, incentive based.
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#1706

  1. An SPV stores an incomplete version of the blockchain.

  2. The transaction was confirmed as valid and gets sent to the mempool to await a miner to add it to a block.

  3. One of the ways miners get paid is thru transaction fees and miners often select transactions with the highest sat/B ratio.

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