How does a wallet with multiple BTC addresses handle transactions ???

[chegmarco]

Hello.
  I wanted to know why in Bitcoin, it is possible for a Wallet to have several addresses ?
In the case that a Wallet has several Bitcoin Addresses, which of the Addresses ensures the sending of the Bitcoins to another Address ? Which of the Addresses of the Wallet carries out the transactions of sending of Bitcoin ?

Thank you for clearing me up.

[1713910886]

1713910886

[Lauda]

I wanted to know why in Bitcoin, it is possible for a Wallet to have several addresses ?

A wallet is just a collection of key-pairs (private and public keys), thus addresses.

In the case that a Wallet has several Bitcoin Addresses, which of the Addresses ensures the sending of the Bitcoins to another Address ? Which of the Addresses of the Wallet carries out the transactions of sending of Bitcoin ?

No address "ensures" anything and you've asked the same question twice (just formulated differently). In Bitcoin, there are these things called inputs and outputs. If you receive 1 Bitcoin to address A which is in a wallet containing e.g. 10 addresses (all others are empty), you now have a unspent transaction output (UTXO). These outputs are then used as inputs for future transactions. This means, that in order to spend from this wallet, you need to take the UTXO from that address as an input for the transaction which you want to create. User-friendly or *convenient* wallets do this automatically. Some wallets such as Bitcoin Core have the option called Coin Control. This enables you to pick out specific inputs and combine in any way that you see fit (as long as it follows the consensus rules).

From the Stackexchange link below:

The way transactions are created is as follows:

• Take a number of unspent outputs from previous transactions and use them as inputs.
• Make a new output of which the output amount is equal or less than the sum of all input values. Your wallet will most probably make this output a pay-to-pubkey-hash output to the address you wanted to send money to.
• Because probably the inputs will not exactly match, you will add another output so that the sum of all new outputs is equal to the sum of the inputs. This output will also be a pay-to-pubkey-hash output to a new change address or to the same address as you are spending from (different wallet apps do this differently).
• Note that if the total output amount is less than the total input amount, the difference is considered the transaction fee and this will go to the miner of the block your transaction will appear in.
• Then lastly the wallet app has to prove it has the right to spend the inputs you used in the transaction. It can do this to provide an input script (technically it's called a scriptPubKey). For the common pay-to-pubkey-hash, this script will contain your public key and the signature you made with your private key. This input script is used by miners to verify if you have the right to make this transaction.
• The transaction is then broadcast to the Bitcoin network.

Read:
1) Wallet: https://en.bitcoin.it/wiki/Wallet
2) Input: https://en.bitcoin.it/wiki/Transaction#Input
3) Output: https://en.bitcoin.it/wiki/Transaction#Output
4) Why do outputs need to be spent entirely: https://bitcoin.stackexchange.com/questions/20611/why-do-outputs-need-to-be-spent-entirely/20623[/list]

[chegmarco]

Ok great thank for your reply. So I guess the Bitcoin (Money) are not available on the addresses, not also on the wallets but rather on the keys

[Lauda]

So I guess the Bitcoin (Money) are not available on the addresses

No, that's not how Bitcoin works.

Not also on the wallets but rather on the keys

You are imagining the wallet in the traditional sense, which is false. A wallet does not hold Bitcoin itself, it's just a collection of keys. The actual "money" or Bitcoin are "on the keys", yes.
Please thoroughly read the supplied links before asking further questions.

[chegmarco]

Ok but how do you know the Key that holds the Balance with Bitcoind for example ?

[Lauda]

Ok but how do you know the Key that holds the Balance with Bitcoind for example ?

This should do it I believe [1]:

After that you run 'dumpprivkey [address]' and it would display the private key of the associated address. FYI do not give this key to anyone, otherwise they can spend your money.
[1] - https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list

[chegmarco]

Ok but how do you know the Key that holds the Balance with Bitcoind for example ?

This should do it I believe [1]:

After that you run 'dumpprivkey [address]' and it would display the private key of the associated address. FYI do not give this key to anyone, otherwise they can spend your money.
[1] - https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list

Ok thank you but I would like to know if there is a way to change my Bitcoin Private Key ?

[Lauda]

Ok thank you but I would like to know if there is a way to change my Bitcoin Private Key ?

No, and that is a very weird question. Why would you want to do such a thing?

[btctousd81]

Ok but how do you know the Key that holds the Balance with Bitcoind for example ?

This should do it I believe [1]:

After that you run 'dumpprivkey [address]' and it would display the private key of the associated address. FYI do not give this key to anyone, otherwise they can spend your money.
[1] - https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list

Ok thank you but I would like to know if there is a way to change my Bitcoin Private Key ?

you cant change private key, its paid of "public key => private key."

why do you want to change it ? have you shaed the private key with someone ?

[chegmarco]

Ok thank you but I would like to know if there is a way to change my Bitcoin Private Key ?

No, and that is a very weird question. Why would you want to do such a thing?

Yes, I want to change to put a little word that I can quickly remember.

[Lauda]

Yes, I want to change to put a little word that I can quickly remember.

No, you can't change a private key. If you change the private key, you will get a different address. If you put "quickly to remember" things into it, which would severely lower the entropy, you will be at higher risk of collision. This means that someone may find that private key and steal your funds.

[chegmarco]

Yes, I want to change to put a little word that I can quickly remember.

No, you can't change a private key. If you change the private key, you will get a different address. If you put "quickly to remember" things into it, which would severely lower the entropy, you will be at higher risk of collision. This means that someone may find that private key and steal your funds.

OK I understand. thank you very much

[chegmarco]

I finally wanted to know if a Bitcoin Address has a single private key or if it can have several private key

[Lauda]

I finally wanted to know if a Bitcoin Address has a single private key or if it can have several private key

Yes. There are 2^160 possible addresses, and 2^256 possible private keys, which means that every address corresponds to 2^(256-160)= ~2^96 private keys. However, generating another private key that corresponds to the same address is nearly impossible.
Read for more information: https://bitcoin.stackexchange.com/questions/25069/can-two-private-keys-generate-the-same-public-bitcoin-address

[chegmarco]

I finally wanted to know if a Bitcoin Address has a single private key or if it can have several private key

Yes. There are 2^160 possible addresses, and 2^256 possible private keys, which means that every address corresponds to 2^(256-160)= ~2^96 private keys. However, generating another private key that corresponds to the same address is nearly impossible.
Read for more information: https://bitcoin.stackexchange.com/questions/25069/can-two-private-keys-generate-the-same-public-bitcoin-address

These details confuse me. So you think "Yes quite simply", a Bitcoin Address has several Private Keys or "No" ?

Just "Yes" or "No" please.

[Lauda]

These details confuse me. So you think "Yes quite simply", a Bitcoin Address has several Private Keys or "No"

Just "Yes" or "No" please.

I have already told you the answer; :"which means that every address corresponds" = "Yes". It is nearly impossible to generate such a key though (at least not in your lifetime).

[chegmarco]

Ok great thank you

[Magkirap]

Hello.
  I wanted to know why in Bitcoin, it is possible for a Wallet to have several addresses ?
In the case that a Wallet has several Bitcoin Addresses, which of the Addresses ensures the sending of the Bitcoins to another Address ? Which of the Addresses of the Wallet carries out the transactions of sending of Bitcoin ?

Thank you for clearing me up.

For simple answer, all of addreses can be used to transfer balance and will appear to that designated wallet. Bitcoin wallet changes its address for security purpose. However, there is nothing to worry in using the old address one since it would still recieved btc.