wallet.dat encrypt by multiple users question

[bob123]

I always use default official window wallet qt program.

Note:
There is no official bitcoin wallet. Bitcoin is not owned by a company/authority/anyone.
Bitcoin is an open source project. Anyone can create wallets.

Bitcoin Core is a development team which focuses on improving the bitcoin protocol. They are not deciding it themselves.
It takes the majority of the community to make changes to the network.

Core has released (and is improving) their full node wallet, which is considered the best full node wallet at this moment (this can change in the future).


While it is definetely safe (regarding security + privacy) to use the core wallet, it is important to keep in mind that it is not an 'official bitcoin wallet'.

[HCP]

How to add new secret key(private key) to that wallet.dat file?

I always use default official window wallet qt program.

If you mean the software now known as Bitcoin Core, then it will automatically create new addresses when you change the password (or enable encryption for the first time) and hold them in the wallet file. The addresses will be shown when you use "File -> Receiving Addresses -> New" or when you create a payment request on the "Receive" tab.


Alternatively, as mentioned by Danny, you can "import" a generated key from elsewhere using the "importprivkey" command with the debug console: https://en.bitcoin.it/wiki/Help:How_to_import_private_keys_in_Bitcoin_Core_0.7%2B

[JohnB31]

In fact it is even more complicated and i hope this will explain it a little bit more.
(Perhaps it makes it even more confusing.)
There is no balance in a wallet so it is not 100% correct to say you have 1000 in your wallet, however i will start talking so to explain it later.
If there is 1000 in a wallet and A wants to pay 100 to Z it is possible that A needs to sends 400:
 100 to Z, 295 to himself. and 5 as a fee for the miner.
The wallet does not contain 1000. The wallet only contains keys to unspent transactions.
Perhaps there are two keys to unspent transactions: an unspent 400 and a unspent 600. (This is only an example it can be more complicated.)
Perhaps the software decides to use the key to the unspent 400:
Z will get a key to unspent 100, a (new) key to unspent 295 is send back to the sender (A) and the miner will get a key to 5 (as a fee).
I don't know for sure if B, who had a copy the wallet.dat file, will also receive the key to the unspent 295 but i don't expect so.
If, in this example, the transaction is accepted :
- A will have in the wallet a key to unspent 600 and unspent 295.
- B will have in the wallet a key to unspent 600 and a key to 400 that is already spend.  
If now B wants to send 10 to Y only the key to the unspent 600 can be used. If he wants to pay a fee of 1 the wallet: 10 will be used for a key send to Y, 589 will be used for a key send back to B and 1 will be used for a key for the miner as a transaction fee.
After this next transaction
- A has in the wallet a key to 600 that is already spent and unspent 295. So he (or she) can still spend 295.
- B has in the wallet a key to 589 that still can be spend.
( Z has a key to 100 , Y has a key to 10, a miner has a key to 5 and a miner has a key to 1 )
( 295 + 589 + 100 + 10 + 5 + 1 = 1000 )

[DannyHamilton]

Z will get a key to unspent 100, a (new) key to unspent 295 is send back to the sender (A) and the miner will get a key to 5 (as a fee).

No.

This is incorrect.

Keys are NOT sent.

Each user creates their own keys. Z will generate a bitcoin address from his PUBLIC key and will provide the bitcoin ADDRESS to the sender (A).  A will NOT send ANY keys to Z at all.

I don't know for sure

Then please don't give bad advice in the Technical sub-forums.  You will cause other people to lose money if they believe the false things that you say.  Do you want to be responsible for someone else losing thousands of dollars?

[Roaid]

If I give over my wallet.dat file to another guy.

Then he and me can use from same wallet. First users can use balance at that usage time, right?

Then what happen if one user encrypt it?

Other user can't use? First person who do encryption wins? Because he only know password?

Obviously, one person's encryption can't affect the use of another person.
Bitcoin determines ownership through a private key. You give the wallet to another person. The other party already knows your private key and can transfer your funds.
You are now encrypting the private key. When you use it, you still need to decrypt the private key. So your encryption has absolutely no effect on other people who already know your private key.
Remember: Don't give your private key to anyone.

[wsxdrfv]

If I give over my wallet.dat file to another guy.

Then he and me can use from same wallet. First users can use balance at that usage time, right?

Then what happen if one user encrypt it?

Other user can't use? First person who do encryption wins? Because he only know password?

Obviously, one person's encryption can't affect the use of another person.
Bitcoin determines ownership through a private key. You give the wallet to another person. The other party already knows your private key and can transfer your funds.
You are now encrypting the private key. When you use it, you still need to decrypt the private key. So your encryption has absolutely no effect on other people who already know your private key.
Remember: Don't give your private key to anyone.

There is situation like who want to sell whole wallet itself. Why just send whole coin through blockchain? Because there is limit of 100 million amount at send function.

[HCP]

There is situation like who want to sell whole wallet itself. Why just send whole coin through blockchain? Because there is limit of 100 million amount at send function.

There is no maximum limit. Unless there is some arbitrary limit set by your wallet. If this is the case, simply send multiple transactions. If you don't transfer the BTC using a transaction, it will NOT be secured by the network and cryptographic security features Bitcoin provides. There is nothing to stop someone simply keeping a copy of the wallet file and spending the coins themselves. The only secure way to transfer Bitcoin to another party is by creating, signing and broadcasting a transaction and waiting for it to be confirmed.

In any case, a max limit of 100 million is fine... as there will only ever be 21 million BTC

[wsxdrfv]

There is situation like who want to sell whole wallet itself. Why just send whole coin through blockchain? Because there is limit of 100 million amount at send function.

There is no maximum limit. Unless there is some arbitrary limit set by your wallet. If this is the case, simply send multiple transactions. If you don't transfer the BTC using a transaction, it will NOT be secured by the network and cryptographic security features Bitcoin provides. There is nothing to stop someone simply keeping a copy of the wallet file and spending the coins themselves. The only secure way to transfer Bitcoin to another party is by creating, signing and broadcasting a transaction and waiting for it to be confirmed.

In any case, a max limit of 100 million is fine... as there will only ever be 21 million BTC

Altcoin's case that has way more max supply than 100 millions.

[HCP]

Altcoin's case that has way more max supply than 100 millions.

Bitcoin Forum > Bitcoin > Development & Technical Discussion

Altcoin forums are over there ---->

Seriously tho... as I pointed out, if you need to send more coins than some arbitrary limit that the clueless altcoin/clonecoin devs have not properly considered, then send multiple transactions or create multiple outputs. Giving someone a digital copy of the wallet file DOES NOT constitute transfer of ownership.

The whole point of cryptocurrency is to create a "trustless" system... Receiver does not need to trust that the Sender is not counterfeiting or forging the transaction nor will they attempt to reverse the payment, as the network takes care of authenticating, validating and securing the transaction. By circumventing this and trying to transfer by simply copying the wallet file, you basically lose ALL of the security.

What's to stop someone simply making X copies of the file and "selling" it to X different people? Anyone attempting to "sell" a wallet file, for the purposes of "transferring funds", should be regarded as "highly untrustworthy" and potentially a scammer. Anyone trying to "buy" a wallet file (for the same purpose) is an idiot.