Homework on Bitcoin Transactions and UTXO - Questions

Blockchain and Bitcoin 101
#1046

  1. UTXOs are transactions on the bitcoin network. They have one or more inputs and one or more outputs, where bitcoin received is the input, and bitcoin sent is the output. A bitcoin wallet searches the blockchain for UTXOs that have unspent bitcoin matching the wallets private key and adds them up to provide an account balance.

  2. Your wallet would use multiple UTXOs in order to meet the total output needed, and send back the “change” after fees.

  3. A bitcoin wallet would look at previous transactions on the network and choose a fee that would allow the transaction to be added to the blockchain in a reasonable amount of time.

  4. You could use UTXOs from multiple private keys as the input for your transaction.

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#1047

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

     It is the number of unspent bitcoin in your wallet that it verifies from the blockchain.

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

    The wallet will combine all the UTXOs to cover the transaction. If there aren’t enough then the transaction is denied.

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

    The wallet will suggest a fee in satoshis per byte based on the difference between the outputs and inputs.

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

By using several addresses.

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#1048
  1. utxos are used to describe the amount of spendable transactions a wallet has received
  2. you will have to send multiple utxos until the amount is reached
  3. it will look at recent transaction fees to attempt to guess what might be accepted by current miners at the time of the transaction
  4. you can break up the transaction into many small peaces to make it harder to track?
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#1049

  1. UTXO are funds which have been send to a recipient who has not spend those funds already

  2. The transaction would be rejected

  3. It sums up all the output and deducts this sum from the input. Txn fee = Input - Output

  4. Since all inputs have to be spend in a transaction, you will also send the “change” back to yourself. So someone from the outside does not know which UTXO was send to someone else and which UTXO was send to yourself.

#1050
  1. basically what you are allowed to spend - there is not balance in the bitcoin world
  2. your transaction won’t be allowed (i.e you don’t have enough money available)
  3. Input = Output + transaction fees
  4. part of the transaction will be sent back to yourself potentially, but with an address that is not recognizeable externally
#1051
  1. UTXO are the balance left in your wallet that it keeps track of.
  2. The transaction would be declined if your UTXO is not large enough to cover it.
  3. The wallet checks the blockchain and figures out the correct fee.
  4. Several addresses and outputs can result from one input.
#1052
  1. Describe what Unspent Transaction Outputs (UTXO) are.
    the total summation of whole and/or fractional output of transactions (UTXO’s) It is represented as the wallet balance.
  2. What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
    no transaction will occur, need to add more UTXO to the wallet, then Resubmit
  3. How would a bitcoin wallet specify the transaction fee when creating a transaction?
    Total UTXO inputs minus total UTXO outputs of transactions = the calculated fee
  4. How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
    use a random( non-deterministic) wallet
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#1053
  1. UTXO’s are transaction inputs that you have not spent yet.
  2. Small UTXO’s will then be summed up in order to complete the amount desired for the specific transaction.
  3. It will suggest a reasonable fee based on previous transactions.
  4. By sending the output to a different address or wallet.
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#1054

  1. UTXO are outputs from other people that sent btc to your wallet or any other wallet, later they are used as inputs when that wallet is creating a transaction. The total amount of utxo is your balance which your wallet calculates.

  2. Your transaction will not go through and won’t be added to the blockchain

  3. Since inputs= outputs + tx fee it is a simple and easy calculation to specify the fee. The wallet can suggest a proposed fee and does this by checking the blockchain and see the recent transaction fees so “guess” for an appropriate fee that will get the transaction entered in a block by miners.

  4. Since inputs=outputs + tx fees it makes a transaction have to spend all the inputs of a wallet added up, the real transaction could be very low but the rest of the transaction will be send back to yourself to an address or addresses you have control over. Like having to use all your money to buy something and getting change back. Thus, you can use may outputs making it hard to track which ones are going back to you.

#1055

1. Describe what Unspent Transaction Outputs (UTXO) are.
All transactions are made up of inputs and outputs. If you receive a transaction (input) and don’t spend it, there is no output yet. this is the UTXO.

2. What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
You would need to use multiple inputs to construct the transaction and send the ‘change’ to yourself.
However, if the inputs don’t add up to the value you want to send, you simply don’t have enough inputs to construct a valid tx.

3. How would a bitcoin wallet specify the transaction fee when creating a transaction?
A btc wallet would look up previous fees on the blockchain and propose a value that it thinks would get your transaction confirmed in a timely manner.

4. How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
By creating multiple output addresses

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#1056
  1. The balance of what is left from the expenditure of the transaction.
  2. The UTXO can be drawn across different inputs to make up the shortfall.
  3. A separate line that shows the difference between the output and the input.
  4. The addresses are anonymous so you could send the bitcoin to yourself and it would look like another address. The owner of the address remains anonymous anyway.
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#1057

1.-Transactions that the blockchain registers for a determined wallet and are available to spend by such wallet.
2.-Transaction will be cancelled
3.-UTXO output-input. It will also estimate fee based on blockchain priority.
4.-Changing adress

#1058
  1. Unspent transaction output - all the spendable outputs for a given address to be used in new transactions
  2. Sum of all UTXO’s calculated in the wallet, transaction will take place if there’s enough balance to cover deduction + fee.
  3. Difference between input and output.
  4. By generating new addresses for outputs, then it gives more privacy when output goes back to the sender.
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#1059
  1. Simply-UTXO is bitcoin that has not been spent yet
  2. Transaction would be declined/denied
  3. transaction fee = input-output
    4.multiple address’
#1060

  1. UTXOs are the unspent transaction outputs when your wallet creates a transaction.

  2. The transaction will likely get rejected.

  3. The wallet will determine what the fee is likely to be by looking at previous fees and base it on that to ensure reasonably fast transactions.

  4. Probably by creating multiple UTXOs to different wallet addresses you own.

#1061
  1. UTXOs are the balance in your wallet from an input not spent.
    2)The transaction would not be completed.
    3)Output minus TX fee equal to the UTXO balance.
  2. Use more than 1 address.
#1062

Transaction received from other party
rejected
difference between overall amount sent and what payment amount was
send multiple transactions at one

#1063

  1. UTXO’s are unspent funds received as outputs from previous transactions.

  2. If a single UTXO is not large enough to cover a transaction, the wallet will combine transactions until a sufficient balance is available. The transaction can then be transferred with adequate funds to the receiving output. Any remaining funds will returned to the sender as a another output, less the transaction fee.

  3. The wallet will suggest a reasonable fee by comparing recent transaction fees.

  4. The notion that the transaction can contain multiple inputs and outputs provides some anonymity to the user. Any one who views the transaction will only be able to estimate the identities of the outputs, using inferences made by comparing the values shown.

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#1064

  1. Is one or multiple inputs gotten from a previous transaction(s).

  2. It will sum up all your utxo’s. If the sum is not big enough for the transaction it will be invalid

  3. Input = output + tx fee

  4. Because you can send outputs back to your own wallet. So you have multiple outputs and nobody can actually tell what amount was used for a transaction and what was send back to your own wallet

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#1065

  1. Unspent transaction outputs are received Bitcoin that are attached to the private key. They can be displayed as the balance.

  2. More UTXOs will be used until the amount is large enough or larger
    and the transaction fee will increase.

  3. According to current and previous transactions the wallet would suggest a reasonable fee. The fees equal the the amount of inputs minus outputs in t a transaction.

  4. By using multiple inputs and outputs and sending reading the block explorer gets more difficult.

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