Change address when Bitcoin was created

[Pffrt]

I just have heard that back in early days of bitcoin, if someone forgot to give a change address, that bitcoin were lost forever. https://themoneymongers.com/bitcoin-change-address/
I never knew this. I can't remember if I had ever seen such a case till now. Please refer me a case where user have lost change bitcoin because of not putting the change address if this is true.

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[AB de Royse777]

For this reason when someone has a paper wallet then it is suggested to send all the funds instead of partial in a tx.

[coupable]

This is interesting ! But how to check lost funds if they are lost/disappeared ? I thought that it's standard in bitcoin protocole that any standard wallet automatically add a change address to the transaction outputs .

And as i don't see many discussions about paper-wallet, i would like to further ask where goes the rest of the sent amount if i send partial paiement using a paper-wallet if i don't set a change address?

By time goes by, i get confirmed that there is still a lot to learn before to resume the bitcoin technology .

[AB de Royse777]

And as i don't see many discussions about paper-wallet, i would like to further ask where goes the rest of the sent amount if i send partial paiement using a paper-wallet if i don't set a change address?

Paper wallets have private key only. It is not a HD wallet.

Read this: In a HD wallet you have bunches of receiving addresses and change addresses. Besides the pass phrase you also have the private key for each address you have in there. When you make a transaction the change amount goes to any change address and you can access them in that change address because you have the pass phrase of the HD wallet and if you want then you can use the private key of that change address to access the fund.

But in case of paper wallet you only have the private key of your wallet address and whatever the change address the protocol creates, you do not have the private key of that address. So when it goes to that change address, the entire fund is gone forever unless someone is very lucky to have the private key generated accidentally and the possibility is very nearly to zero.

[BrewMaster]

And as i don't see many discussions about paper-wallet, i would like to further ask where goes the rest of the sent amount if i send partial paiement using a paper-wallet if i don't set a change address?

this is how bitcoin works:
you have a transaction output that has a value, lets say the value is 10. you spend this output and create a couple of new outputs that each have a value of their own. lets say you created 3 and the values were: 1, 4, 3.
this means you have paid 2 units in fee which is calculated automatically.

now to answer your question it depends on how you create that transaction. if for example your paper wallet has 1 bitcoin in it and you spent 0.6 bitcoin and didn't set any change address or any other outputs, then your remainder (0.4BTC) goes to the miner as fees.
usually the problem that OP pointed out is about people creating a new wallet (that has its own addresses) then import their paper wallet, spend a small amount of it (0.6 out of 1) then the remainder goes to a change address from that wallet (0.4) then they throw away that wallet!!! that is when they lose money.

[hosseinimr93]

But in case of paper wallet you only have the private key of your wallet address and whatever the change address the protocol creates, you do not have the private key of that address. So when it goes to that change address, the entire fund is gone forever unless someone is very lucky to have the private key generated accidentally and the possibility is very nearly to zero.

In order to access bitcoins stored in a paper wallet, many people import their private key into a wallet. When they send a portion of their balance, a change address is created. The person has the private key and can export it from the wallet.
The remaining amount of balance never goes to a random change address with an unknown private key. But it can go to miners if someone make a transaction manually by broadcasting a raw transaction.

Generally, those who use paper wallets can lose their fund for two reasons.

• Importing the private key into a wallet, sending a portion of balance and then delete the wallet file without saving seeds or private keys: In this case the remaining balance will remain in an address with an unknown private key forever.
• Broadcasting a raw transaction without using a change address: In this case the fund will go to miners.

So, if you use a wallet, a change address is created by your wallet. But if you don't use any wallet and make a raw transaction manually without using a change address, a random change address won't be created. The fund will be awarded to a lucky miner.

[coupable]

Thank you all who clarified this for me.
I think this would be a horrible situation for someone to lose his funds in this way. Indeed, i thought that paper-wallets are the most easy secure way to store bitcoin besides hardware wallets that require a significant amount of money to purchase it and a lot of technical knowledge, but know i can understand why paper-wallets are not for popular use even they cost nothing (money) but require a lot of knowledge about the bitcoin as a whole .

[vapourminer]

cant stress this enough when sweeping paper wallets. sweep the ENTIRE balance in one shot. i almost got burned as habit made me sweep a fraction of the paper wallets value as a test transaction (something i regularly do when sending coin to a new wallet or whatever). luckily the wallet i swept to sent the change back to the papers address.

soon as i clicked i realized my mistake.. and i had a VERY uncomfortable wait until i could verify the change was at the original addy.

it was not fun sitting there sweating bullets wondering if i had just blown 99% of the amount in the paper wallet by sending it to a black hole or for the mining fee. rated that experience about a 2 out of 10. would not do again.