Homework on Bitcoin Transactions and UTXO - Questions

Blockchain and Bitcoin 101
#2073

  1. Bitcoin sitting in a wallet that isn’t an input yet.

  2. You will need to bring in another input to make up the difference.

  3. input - output = fee

  4. Uses many inputs and outputs in the transaction.

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#2074
  1. Describe what Unspent Transaction Outputs (UTXO) are.

They are essentially the balance of our wallet.

  1. What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?

Your transaction will not go through.

  1. How would a bitcoin wallet specify the transaction fee when creating a transaction?

It looks at recent fees on the blockchain

  1. How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?

You could send money back to yourself as an output of transactions

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#2075

  1. UTXO are transactions on the blockchain which were sent to your address or any other address and are still unspent which can be spent/used as inputs to generate the next UTXO.

  2. Two or more UTXOs must be combined to achieve the required or more than the required amount for the transaction

  3. The transaction fee is the total Input minus the total output.

  4. An input can be outputed to many different output addresses and there is no way to figure out which address/es belong to the original sender.

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#2076

  1. UTXOs reflect the unspent amount of funds available for transactions in a wallet.

  2. If you don’t have any single UTXO it means your wallet is empty and no transaction is possible.

  3. The wallet specifies the fee by showing the difference between total input and total amount of output.

  4. The idea of inputs and outputs can be used to increase privacy by generating new output addresses for new transactions.

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#2077

  1. Describe what Unspent Transaction Outputs (UTXO) are.
    UTXOs are transactions where you have been sent BTC and which have not yet been spent

  2. What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
    multiple UTXOs would be added to cover the cost of the transaction. As input must equal output, the balance of the UTXOs (i.e. total – cost – fees) would be sent back to you

  3. How would a bitcoin wallet specify the transaction fee when creating a transaction?
    Fee = input(s) – output(s) (typically calculated automatically be the wallet)

  4. How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
    specify multiple recipients for the transaction and use more UTXOs than required to cover basic cost. Direct excess UTXO balance to other addresses you control

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#2078

Yes, if you are using a HD wallet (which most modern wallets are), you will notice that each time you click the receive button, you will get a new address to send funds to. :slight_smile:

2 Likes
#2079

Well, they are not really in the wallet but on the blockchain. But other than that you are correct :slight_smile:

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#2080
  1. UTXO are the balance left in wallet after transaction.
  2. Transaction will not be accepted, it is not valid.
  3. It will calculate the fee by adding Txfee to the output.
  4. I can use a different address for each transaction.
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#2081

1.UTXO are basically you funds that you can use to create a new transaction

  1. then your wallet will scan the blockchain for the utxo and then tell you that you dont have enough utxo and the transaction cant be done

  2. it depends on the wallet, with some wallets you can put in how much fee you want to send, If you choose more fee, then miners will choose that block and the transaction will go faster, due to the miners get the fees as reward when new block is created. Other wallets checks with the blockchain how much fees is right now and chooses aa fee that is enough for a normal transaction verification

  3. you could do transactions to yourself with multiple adresses. nobody know who you are sending to if youre not using a wallet linked to a exchange for example

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#2082

1- The UTXOs are the amount of bitcoins that you have in your wallet to make a transaction.
2- The transaction will be denied by the nodes.
3- By the amount of inputs minus the amount of outputs in a transaction.
4- Bitcoin offers Anonymous transactions. The private and public key help this “private transactions” to happen.

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#2083

  1. UTXO it is the sum of all unspent input in my wallet.

  2. My wallet will deny the transaction

  3. Inputs minus Outputs

  4. creation of multiple output address

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#2084

  1. When you receive BTC your wallet does does not store collectively how much BTC you have. Instead when you receive BTC it is stores at a UTXO. It tracks how much BTC is unspent out of how much you have received. Each input is stored as a UTXO. Your wallet will then add up all UTXO’s to give you a total balance.

  2. Then you wont be able to spend that money and will not be able to initiate the transaction.

  3. The BTC wallet will look at the current price of fees. It will then purpose a fee that will get you processed in a reasonable amount of time.

  4. Because you can send BTC to multiple addresses with one transaction. Even sending money back to yourself. This increases anonymity.

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#2085

Technically the Bitcoin blockchain is pseudo anonymous, meaning that if someone knows your address can track your transactions and knows how much coins you posses :slight_smile:

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#2086
  • The UTXO are the outputs of previous transactions sent to your address. The sum of the UTXO is the total amount of bitcoin available in your wallet.
  • If that UTXO is the only one I have then I can’t do the transaction, but if have more UTXO in my wallet then they can be aggregated to cover the total amount.
  • The transaction fee is calculated by the wallet based on the fees of previous transaction in the blockchain and is created when the wallet define an output whit less value that the input, so the difference in value between the inputs and outputs become the fee.
  • Creating transaction with many different inputs and outputs.
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#2087

  1. UTXO are transactions that have bee received but not yet spent.

  2. You would not be able to process that transaction.

  3. The transaction fee is usually calculated by the difference of the Transaction input and the Transaction output. However, with some wallets, you can specify the transaction fee yourself.

  4. Using many address inputs and outputs will make it hard to track the exact person the transaction went to

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#2088
  1. UTXO are like the current balance in your wallet that you can send to a recipient. (like send to another person and/or to your self)
  2. The transaction would get back to you with error or message indicating insufficient funds?
  3. it would compute based on ( utxo minus the amount spent and compute the transaction fees out of the remainder
  4. any incoming inputs and outgoing outputs will be transmitted through a digital signature.
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#2089
  1. UTXOs are output transactions directed toward your address. Having UTXO permits you to send outgoing transactions up to their sum.
  2. The blockchain would not allow the transaction as it would not make sense in the code. The transaction would be ignored by the miners.
  3. The fee is automatically applied and the wallet denotes the fee by subtracting the output value from the input value.
  4. You can send transactions to multiple wallets with plausible deniability of ownership of those wallets. Theoretically you could bounce transactions around many wallets to further obfuscate ownership.
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#2090

  1. UTXOs are transaction amounts that are received by an address that can use it as an output. In a way they are balances of different accounts

  2. A wallet generates an address using the account holders private key and sends the “extra” to that address, sort of like change. This address becomes the account holders UTXO. (if a person spends enough BTC that produces change, they will be able to use it to make up for future differences).

  3. A wallet can tweak the amount of change sent back to increase or decrease the fee (because the leftover from the change is the fee).

  4. By using a new address for each transaction. Its like having many micro accounts instead of 1 that can be more easily linked to multiple transactions.

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#2091
  1. UTXO are the balance left in your wallet that it keeps track of.
    1. The transaction would be invalid.
    2. A bitcoin wallet never specifies the fee because it is easily calculated - input minus output and you get your fee.
    3. The wallet generates a different public address everytime it does a transaction whether is an input or an output
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#2092
  1. The whole balance of your wallet - incoming and outgoing transactions
  2. Stack some sats. Use another UTXO to combine them together, send both (or more) and get the change back to my wallet minus fee.
  3. Automatically or by time preference - miners would choose to validate faster those transactions that would offer larger fee. If you have time, choose a lower fee
  4. Use different addresses. Use XMR
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