Homework on Bitcoin Ecosystem - Questions

Blockchain and Bitcoin 101
#322

Answers

  1. A full node holds the whole version of the blockchain, it’s connected on the network, waiting for new transactions to add on the mempool or new blocks to add on the chain. Simplified Payment Verification just queries a full node to have some information about the status of some transactions. Usually we can use SPV on the mobile phone.

  2. A wallet signs new transaction with the private key and controls that we have some UTXOs to spent. A full node receives this new transaction, saves its into the mempool and broadcasts to other full node and miners on the network. So, when a transaction is broadcasted, it means that is shared between nodes in the mempool.

  3. Miner chooses from the mempool the transaction with highest fees and composes a new block. Every miner works on a different block of transaction. They compete each other to solve the algorithm puzzle behind the hash code, trying to guess a nonce number. When this puzzle is solved, the new block is added on the chain and broadcast at the node on the network. To be sure there will not be stale blocks on the chain, for accepting new payment transactions the network wait the next six blocks mined.

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#323
  1. SVP does not have the full blockchain, just a part of it. Nodes have the full blockchain
  2. A TX is broadcasted when it is sent to the mempool waiting to be piked up by a miner
  3. The miner will choose the tx with the higher fees
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#324

  1. The difference between a SPV and a full node is that an SPV does not have a copy of the blockchain and needs to connect to the node to get the information (Mobile). The nodes have the full copy of the blockchain locally installed.

  2. The transaction is valid, the node put this transaction into Mempool, wait for the miners to “mine” it.

  3. It chooses the ones with the higher transaction fees.

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#325

  1. SPV’s dont keep track of the entire block-chain , full nodes have the entire block-chain

  2. it means that the transaction is broadcasted to the nearest node,from an SPV to the nearest node and then to other nodes in the block-chain networck

  3. Miners will pick the transaction with the highest fee and the fees are determined by the physical space taken by the data of the transaction(not by the amount of money transacted)

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#326
  1. The difference between a SPV and a full node is that a SPV can initiate transactions. It has limited information about the blockchain which it acquires from one or more nodes. Nodes each store an entire copy of the blockchain. They are constantly updating it. They cannot initiate transactions. Nodes also hold pending transactions in a memepool.
  2. A transaction being broadcasted means that all the nodes have been informed of said transaction. This is how transactions are propagated through the blockchain.
    They hold it in their respective memepools until verified.
  3. A miner can pick any of the available valid transactions to be added to the next block. They typically pick the ones with the highest fees because they get paid those fees.
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#327
  1. Full nodes have a complete version of the blockchain. spv mostly store local transactions and relies a full node to send and verify txs.
  2. when a transaction is braodcasted it is sent to the blockchain to become public data.
  3. they usually pick the txs with the highest fees paid to them for verifying the transaction and broadcasting it to the blockchain. Which the fees paid and the block reward are their incentive to do the work.
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#328
  1. They don’t sotre the blockchain, they mostly store transactions relevant to its address and require a full node to send tx.
  2. The transaction is send from node to node. So every node sends it to it’s neighbors and so on.
  3. A miner takes the transactions with the highest tx fee from the mempool.
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#329

1. What is the difference between a SPV (simplified payment verification) and a full node?
A SVP is a node that can verify if a transaction has been included in a block or not without having to download the entire blockchain. A full node is a node that is allowed to validate or reject the transmissions. Full nodes must have a copy of the entire blockchain.

2. What does it mean when a transaction is broadcasted?
That means that the transaction is send to the network for validation.

3. How does a miner pick which transactions that gets added to the next block?
Miners usually choose the transactions that have the highest fees (transactions with several inputs and or several outputs).

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#330
  • What is the difference between a SPV (simplified payment verification) and a full node?
    The SPV has only a simplified and short version of the blockchain, and it will request that version of the blockchain to a full node.

SPV is for example an app that you run on your iPhone.

The full node runs the complete version of the blockchain.

  • What does it mean when a transaction is broadcasted?

A wallet broadcast the transaction to the network of all nodes. They listen to the transactions and will add the transactions to the mempool if the transaction makes sense.

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

Transactions are being put in the mempool by the nodes. The miner will first pick up the transaction with the highest fees per Byte to add them to the next block. As of course the miners are incentivized with transaction fees.

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#331
  1. A SPV is a type of node that doesn’t have the full version of the blockchain, which a full node has. The SPV can be a small device like a smartphone. The SPV will query a full node to help it verify transactions.
  2. A broadcasted transaction is a transaction that has been sent in the network waiting to be verified by the different nodes.
  3. A miner will seek the transactions with the higher fees in order to optimize his incentive.
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#332

the mempool contains transactions, not utxo’s. Utxo’s are unspent transaction outputs that you have, and you can use it in a transaction to change ownership in the output of a transaction.

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#333

Yes, if your transaction has for example 6 confirmations, it means that since the block it is mined, another 5 blocks were mined on top. The more confirmations it has, the more blocks are mined since your transaction was included in a block. And it takes an average of 10 minutes per block.

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#334

1. What is the difference between an SPV (simplified payment verification) and a full node?
Basically, SPV represents a mobile phone, it isn’t a node, so it doesn’t conclude in the blockchain. But full node is one of the copies of the blockchain, it is concluded in the blockchain.

2. What does it mean when a transaction is broadcasted?
That means every node has got a copy of the transaction.

3. How does a miner pick which transactions that gets added to the next block?
Miners choose the transaction which offer a higher fee than others.

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#335
  • What is the difference between a SPV (simplified payment verification) and a full node?

A full node has a complete storage of the full blockchain while an SPV will only hold a small portion that is needed in order to conduct some simple transactions.

  • What does it mean when a transaction is broadcasted?

A transaction is broadcasted when it is shared with nodes across the network, it is then added to that nodes mempool.

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

Miners may choose from a mempool which transactions they would like to add to the next block, generally by how much fees they can take away after loading the next block to its capacity in space.

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#336

  1. SPV does not contain the entire blockchain

  2. it is sent out to the mempool to be picked up by a miner

  3. usually the transactions with the most fees.

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#337
  1. An SPV store the transactions realevant to its addresses only, a node contains a copy of the whole blockchain.
  2. Your wallet requests a transaction by broadcasting it to a node which broadcasts this transaction to the mempool where it can be accessed by the network and the miners can confirm it.
  3. The miners pick the transactions with the highest transaction fees.
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#338

  1. What is the difference between a SPV (simplified payment verification) and a full node?
    SPV is typically on a mobile device only, full node will be on a computer. SPV can only verify if a transaction is on the blockchain.

  2. What does it mean when a transaction is broadcasted?
    A wallet (for example) can construct a transaction and broadcast it onto the network, it would be an unconfirmed transaction at this point.

  3. How does a miner pick which transactions that gets added to the next block?
    Unconfirmed transactions are held on nodes in the mempool, based on transaction fee miners select the transaction they want to work on to place into the blockchain.

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#339
  1. An SPV does not keep a current copy of the blockchain. A node does. The SPV will reach out to a node to obtain the most recent blocks.
  2. The transaction has been added to the blockchain by a miner and sent out to all other nodes and miners on the network.
  3. The miners will almost always choose the transactions that pay the highest. The ones with the highest satoshis/bytes
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#340
  1. What is the difference between a SPV (simplified payment verification) and a full node?
  2. What does it mean when a transaction is broadcasted?
  3. How does a miner pick which transactions that gets added to the next block?
#341
  1. SPV is mini node that does not have all the data on the blockchain
    Full node has all information and data of the blockchain
  2. It is accepted
  3. Miners will always look for the transaction that has the higher fees.
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