You can use multiple UTXOs as inputs to a new tx. If that isn’t enough to cover your transaction then your transaction would be refused.
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unspent transaction outputs: This is a wallet balance of a previous transaction input.
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The Transaction would decline because their is nothing to create a transaction from.
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The fee would be generated based on the amount of input then subtracted, and the balance would be the output.
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Different output addresses even if its to yourself.
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- UTXOs are the outputs from a transaction which have not yet become inputs to a new transaction so are sitting in a wallet and available to spend.
- Two or more UTXOs would be sent which together cover the cost of the transaction.
- The wallet would look at the fees of other recent transactions and calculate the fee that would be high enough to get the transaction on the blockchain.
- Using different addresses makes it more difficult to see that multiple outputs have gone to the same wallet
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- Unsent money
- Tx won’t get through if there isn’t sufficient amount
- By the amount of tx?
- By Wallet = USB like device
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You can use multiple UTXOs as inputs to a new tx. If that isn’t enough to cover your transaction then your transaction would be refused.
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Hi! Seems just enough secure yet… I see others say to use multiple inputs, outputs, etc. but at this time I think it is good to keep things simple. (Maybe I’m wrong…)
- tranasaction you have received on the wallet which you have not spent yet
- the wallet sums up all the transactions I received to come up with what I need to spend, If it is not enough the transaction will be invalid.
- It subtracts the input from the output
4.have multiple addresses for output.
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Yes, thanks Mali 
and also if I am over the amount that needs to be spend, I can send the renewing amount back to myself…
Describe what Unspent Transaction Outputs (UTXO) are.
Are the set of responses you private keys get when they query the blockchain about how much value you have received.
What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
Query the blockchain about de value of all transactions inputs and then add everything up and tell how much you have to spend.
How would a bitcoin wallet specify the transaction fee when creating a transaction?
They search the last fee and calculate the best equilibrium between price and speed to give you a value for the transaction. But you can also, for yourself, define how much you would pay to the network validators. The problem is that you price could be less than its usual at the moment and then no one will accept the work, and your transaction will be let pendent.
How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
By watching out for what wallet you’re using to each transaction. With this in mind you can maybe set different wallets for different activitities.
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You can just use multiple addresses in the same wallet.
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- Describe what Unspent Transaction Outputs (UTXO) are.
They are the unspent inputs received from the sender or the difference from the output and fees.
- What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
The wallet will check and sum the necessary UTXO(s) to determine if you have enough to spend
- How would a bitcoin wallet specify the transaction fee when creating a transaction?
It will check current fee rate of recent transaction to determine the appropriate fee
- How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
Outputs can be to any Bitcoin address/wallet new or used which can also belong to you.
There seems to be a range of methods on improving privacy or anonymizing a transaction(s). One example is Avoiding Address Reuse. Using brand new addresses and never reusing previously used or sent to addresses, always demand a new address when sending Bitcoin.
Examples and more on this topic:
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Homework - UTXOs - Answers
Q1. Describe what Unspent Transaction Outputs (UTXO) are.
- UTXOs are Unspent Transaction Outputs that are attributed/allocated to your wallet’s private key. Collectively, they make up the wallet balance. Each individual UTXO is the output of a confirmed transaction. When the wallet user wants to send or spend some Bitcoin, the blockchain checks if the sum of the wallet’s available UTXOs are equal or larger than the transaction requires and processes accordingly.
Q2. What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
- If the UTXOs allocated to the wallet’s private keys are insufficient to make the transaction, the transaction is invalid, hence denied and disregarded.
Q3. How would a bitcoin wallet specify the transaction fee when creating a transaction?
- Most wallets use the recommended available fees currently charged by the network. Some current modern wallets give the option to choose different fees to incentivise the miner to include them in the next block quicker. This means that their transaction is processed quicker and hence the final price they pay for the exchange has less slippage from the quoted price. Additionally, on some other blockchains, there are also methods such as alchemist protocol (on ETH chain) which allows for direct miner incentivisation by attaching the offered fee to the transaction.
Q4. How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
To increase privacy, use a wallet address only once. It is almost impossible to follow assets without knowledge of wallet ownership.
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The defenition is literally in the name so when someone sends BTC to your wallet (output) and you haven’t spent any of it, your wallet will see it as a UTXO. A —##—>B —0,5BTC—> C
The 0,5 BTC is not spent by wallet C and is the output of wallet **B (Unspent Transaction Output). The value that your wallet is “holding” is seen as the sum of the UTXO’s your wallet is assigned to by the blockchain. -
Then the transaction won’t be done, because checked by other nodes it will be seen as invalid.
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input - output = fee
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Because the BTC adresses that the transactions are send from and received of are difficult to trace back to the private key and so the owner stays anonymous.
- UTXO’s are open or available outputs that have yet to be claimed or spent.
- Multiple UTXO’s would be utilized to cover your transaction if a single UTXO does not exist.
- The wallet derives the lowest acceptable transaction fee from the blockchain.
- By paying yourself…?
You can use multiple UTXOs as inputs to a new tx. If that isn’t enough to cover your transaction then your transaction would be refused.
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How paying yourself increase privacy in your transaction?
1. Describe what Unspent Transaction Outputs (UTXO) are.
funds received and not spent
2. What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
if the amount of input transactions is not lower or equal to the amount requested in creating the output transaction then that output will not be accepted by the nodes therefore it will not be confirmed and added to a new block by the miners.
3. How would a bitcoin wallet specify the transaction fee when creating a transaction?
fee will automatically be calculated by your wallet from the total amount generated by all UTXO’s : input = output + fees
4. How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
X can send funds to Y, Z, W but also, it’s possible to send funds to X (to self), being able to send funds to self creates a layer of privacy.
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Describe what Unspent Transaction Outputs (UTXO) are.
UTXO are the inputs or BTC that you can spend -
What would happen if you don’t have any single UTXO that is large enough to cover for your transaction?
I need to combine with other UTXO to cover or just exceeded the transaction. Any balance after considering the transaction amount and fees required can be sent back to me or the address I have specified. -
How would a bitcoin wallet specify the transaction fee when creating a transaction?
The balance after deducting total output from the inputs -
How could you use the notion of transaction inputs and outputs to increase privacy in your transaction?
Using multiple inputs and outputs making it hard to pinpoint particular senders and recipients
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My thinking is since when you pay yourself it creates a different address. Not sure how effective though, hence my “…?” Other students on forum have better and more in depth answers. I’m still learning and grasping these concepts. Any thoughts?
I still don’t understand your answer ,if you mean paying without bitcoin wallet, you will need different private keys to have different address in-order to increase privacy in your transaction, but there is no need to do this yourself since bitcoin wallet do it for you. There are three main types of wallets,
1,A non-deterministic (random) wallet, all the private/public keypairs are generated randomly. The wallet may generate 100 random private keys as soon as it is initialized.
2, A sequential deterministic wallet, a passphrase or sequence of characters is randomly generated to act as a seed. It is then repeatedly incremented and hashed to generate new private keys.
3. A hierarchical deterministic wallet, a single keypair is created initially and is known as the master keypair. This master keypair is used to generate child keypairs (remarkably, new bitcoin addresses can be generated using just the public key).