-
Describe what Unspent Transaction Outputs (UTXO) are.
As long as there are outputs that don’t equalize the sum of the inputs, they are considered as unspent. Further they represent the sum of available funds that the private key can access. -
What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
It will fail because that results in it being regarded as invalid. -
How would a bitcoin wallet specify the transaction fee when creating a transaction?
Either by our choice or its own suggestion. The fee is not specified in the transaction directly but will be implied in that it is always calculated by the difference between the in- and outputs. -
How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
If an output is in my own control, I can direct some values back to myself and thereby disguise the sum that got spent. This therefore also happens automatically when you create your own change in the common case the transaction value is not equal to the sum of the accessible UXTOs in the network.
The wallet could take a look at the current mempool to determine how much the fee is needed for your transaction to be included in the next block. Also the larger your transaction is (more inputs and outputs) the more you fee you will have to pay as it is counted in satoshi per byte. Sometimes wallet have an option to set a custom fee. If your transaction is not a top priority you can always set a fee that would confirm your transaction in the next 24 blocks or so.
- Outputs of a transaction sent to your private key
- Other utxo’s would be combined to create a large enough utxo for the transaction and the change would be sent back to you
- The wallet would choose a large enough fee by checking the blockchain
- Creating multiple outputs in a transaction
Q1: UTXO’s are the sum of all available outputs that you can use to initiate a transaction
Q2: The transaction would be denied.
Q3: The bitcoin wallet would check previous transaction fees to help your transaction get on the blockchain faster.
Q4: You could split the UTXO between the transaction you are sending to other(s), and send the remaining UTXO back to yourself thru multiple addresses that you control.
1 utxo of 0.5btc is already enough to pay 0.3btc and you will have back 0.2btc - fee
- UTXOs are outputs from previous transactions that are sitting in a wallet waiting to become inputs that the current wallet wishes spend. The wallet functions to add up all of the available UTXOs and represent them as a balance in the wallet.
- The wallet would combine enough UTXOs to cover a given transaction, then send the remaining difference back to the senders wallet as a new UTXO of a different amount.
- One of the wallet functions is to choose a transaction fee based of the blockchains previous fee amounts, in an effort to make the transaction get picked up in a block by the miners.
- From the outside looking in at inputs and outputs of transactions, because they are hashed, you cannot determine which output goes to which recipient. This function creates privacy in the transaction.
-
UTXOs are transactions that were sent to your wallet that haven’t been spent yet.
-
If you don’t have sufficient UTXOs to perform a transaction, your transaction will simply be ignored.
-
The bitcoin wallet looks at previous transactions on the blockchain and proposes a fee that will get the transaction added to the blockchain “fast enough”.
-
Since the entire UTXOs must be spent in the outputs, you can never be sure which of the outputs are being transferred to a new account or being redirected back to the original user, which would create a new UTXO for future use.
-
They are output values/transactions that are derived out of all your input values/transactions. Together with transaction fees they will equal previous inputs. This is something your wallet keeps track of.
-
The Bitcoin protocol requires that UTXOs must match Input value. Any surplus (after fees) will be sent back to the transaction address.
-
It analyzes recent transactions on the blockchain based on speeds + cost of fees in order to set up a fee to your best advantage in aspects of time vs cost.
-
I can create a multitude of receiving addresses derived out of my private key and move incoming inputs through them to make it harder for public spectators on the blockchain to keep track of my transactions. Its similar to the process of money laundering. But there are tracking measures available today which obsolete such efforts.
You can combine more smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover, the transaction will fail
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail and not be broadcasted to the network.
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail
By a batch of bitcoins, I basically mean an UTXO. Because it’s bunch of sats grouped into an utxo.
Your correction is better Now 
You can try to combine multiple smaller utxo’s together to cover the amount. Only if the sum of all your available utxo’s aren’t enough to cover the amount, the transaction will fail
I see now, thank you for the clarification! Only when the sum of available UTXOs does not meet the required amount does the Tx not propagate. If the combination of UTXOs are sufficient then the TX will progress 
[1] Unspent Transaction Outputs (UTXO) are transactions in the blockchain that have not as yet been spent by the owners. i.e. Bitcoin from different sources that has been sent to your wallet and you haven’t spent them as yet.
[2] If one does not have a single UTXO that is large enough to cover a large transaction, all may not be loss if you have more than one UTXO that when they all are added together, they equal or exceed the required amount. Hence, once the UTXOs grand total is sufficient, then the transaction would be possible.
[3] A bitcoin wallet determines the transaction fee by looking at the prior value of the fee in the blockchain or by allowing the user to specify it.
[4] By sending more than one transaction output back to your wallet(s) input, more than one bitcoin address for the change would be created to receive the funds at the input. So you would achieve more privacy in your transaction since each of the change addresses would be anonymous and thus no one would be able to find out thereafter how much bitcoin you truly own that easily.
Thank you Fabrice for your input on my answer I do understand that the total of inputs will create my UTXO and that if the amount of my UTXO ( balance) is not large enough the output + fee won’t be possible unless I reduce the amount of my output, correct ? I also understand that the output can be send to many addresses at once even back to my self , what would be a practical example of me wanting to send money back to my self ?
thank you in advance Fabrice.