Changing wallet password, what happens?

DannyHamilton

legendary

Activity: 3472

Merit: 4801

Quote from: william3489 on March 15, 2017, 07:11:44 AM

What is the practical difference between creating a new wallet and just requesting a new address and sending the coins to myself?

Requesting a new address is a lot easier to do. It doesn't require you to move around your wallet.dat file and risk accidentally deleting or overwriting it.

Quote from: william3489 on March 15, 2017, 07:11:44 AM

Will the program stop you from sending coins to yourself?

No.

Quote from: william3489 on March 15, 2017, 07:11:44 AM

Some responders obviously think it's better/safer to have a whole new wallet. Is there any real practical difference?

If you start a new wallet, you won't be tempted to re-use one of those old (possibly compromised) addresses to receive bitcoins in the future.

william3489

newbie

Activity: 8

Merit: 0

Quote from: DannyHamilton on March 14, 2017, 03:19:42 PM

Quote from: william3489 on March 14, 2017, 12:17:18 AM

Instead of doing all that could I not...

1) Move my current wallet file out of the Bitcoin data directory.

2) Restart bitcoin creating a new wallet.

3) Create a new address and save it.

4) Back up new wallet and put old wallet back.

5) Send to new wallet.

6) Remove old wallet and replace with new wallet.

Instead of doing all that, you could...

1) Change your password.

2) Request a new receiving address from Bitcoin Core.

3) Send your entire Bitcoin Core balance to the new receiving address.

What is the practical difference between creating a new wallet and just requesting a new address and sending the coins to myself? Will the program stop you from sending coins to yourself?

Some responders obviously think it's better/safer to have a whole new wallet. Is there any real practical difference?

calkob

hero member

Activity: 1106

Merit: 521

Quote from: william3489 on March 13, 2017, 12:15:43 PM

What happens if I change my wallet password but somebody has a copy of my wallet that was made before I changed my password? Can they still spend my bitcoins with the old password and the old wallet copy?

That is defiantly a yes, the old wallet.dat file is encrypted using the old password, think about it the old backup file knows nothing of your new password or backup. I would suggest deleting all previous copies of your wallet.dat file.

DannyHamilton

legendary

Activity: 3472

Merit: 4801

Quote from: william3489 on March 14, 2017, 12:17:18 AM

Instead of doing all that could I not...

1) Move my current wallet file out of the Bitcoin data directory.

2) Restart bitcoin creating a new wallet.

3) Create a new address and save it.

4) Back up new wallet and put old wallet back.

5) Send to new wallet.

6) Remove old wallet and replace with new wallet.

Instead of doing all that, you could...

1) Change your password.

2) Request a new receiving address from Bitcoin Core.

3) Send your entire Bitcoin Core balance to the new receiving address.

OmegaStarScream

staff

Activity: 3500

Merit: 6152

Yes, your method could work also, as long as you have the current backup then there is nothing to be afraid of while testing any other method, I just thought It would be best to use Mycelium as intermediator so you don't get confused in the process.

william3489

newbie

Activity: 8

Merit: 0

Quote from: OmegaStarScream on March 13, 2017, 12:27:32 PM

Quote from: william3489 on March 13, 2017, 12:22:29 PM

Quote from: OmegaStarScream on March 13, 2017, 12:18:20 PM

Yes, they could use the old password as long as they have the old wallet file (If the same private keys are there of course).

Meaning what? If I wanted to prevent this I would have to change my password, then create a new bitcoin address and send all the bitcoins to the new address?

How does one prevent that most easily?

You didn't mention the wallet used here, some of them generate different addresses and still keep the private keys in one wallet.dat file. Again, If you think that someone have access to your old wallet.dat file + he might be able to get the password you should make a new wallet file (and not a new address only) with a new password and send everything there instead of just changing the password.

Simple steps to follow (whatever wallet you are using):

1. Install Mycelium in your android.
2. Run your wallet (from PC) and send all funds to your Mycelium.
3. Remove the old wallet and create a new one
4. Send from Mycelium to your new generated wallet on PC.

Instead of doing all that could I not...

1) Move my current wallet file out of the Bitcoin data directory.

2) Restart bitcoin creating a new wallet.

3) Create a new address and save it.

4) Back up new wallet and put old wallet back.

5) Send to new wallet.

6) Remove old wallet and replace with new wallet.

achow101

staff

Activity: 3458

Merit: 6793

Just writing some code

The wallet.dat contains your private keys. When you change your password, the private keys you have already used stay in the wallet so that you can spend your Bitcoin. However the look-ahead keypool is refreshed so that any new addresses you request after the password change are not in the old wallet with the old private keys. This means that if you don't spend your Bitcoin after you change your password, anyone with a copy of the original wallet with the old password can still steal your Bitcoin if they have the old password.

william3489

newbie

Activity: 8

Merit: 0

Quote from: OmegaStarScream on March 13, 2017, 12:27:32 PM

You didn't mention the wallet used here, some of them generate different addresses and still keep the private keys in one wallet.dat file. 4C.

Bitcoin core.

I am not worried, I am just wondering in theory how it works.

Kind of sounds like it's a bit pointless to change your wallet password.

OmegaStarScream

staff

Activity: 3500

Merit: 6152

Quote from: william3489 on March 13, 2017, 12:22:29 PM

Quote from: OmegaStarScream on March 13, 2017, 12:18:20 PM

Yes, they could use the old password as long as they have the old wallet file (If the same private keys are there of course).

Meaning what? If I wanted to prevent this I would have to change my password, then create a new bitcoin address and send all the bitcoins to the new address?

How does one prevent that most easily?

You didn't mention the wallet used here, some of them generate different addresses and still keep the private keys in one wallet.dat file. Again, If you think that someone have access to your old wallet.dat file + he might be able to get the password you should make a new wallet file (and not a new address only) with a new password and send everything there instead of just changing the password.

Simple steps to follow (whatever wallet you are using):

1. Install Mycelium in your android.
2. Run your wallet (from PC) and send all funds to your Mycelium.
3. Remove the old wallet and create a new one
4. Send from Mycelium to your new generated wallet on PC.

william3489

newbie

Activity: 8

Merit: 0

Quote from: OmegaStarScream on March 13, 2017, 12:18:20 PM

Yes, they could use the old password as long as they have the old wallet file (If the same private keys are there of course).

Meaning what? If I wanted to prevent this I would have to change my password, then create a new bitcoin address and send all the bitcoins to the new address?

How does one prevent that most easily?

OmegaStarScream

staff

Activity: 3500

Merit: 6152

Yes, they could use the old password as long as they have the old wallet file (If the same private keys are there of course). So, If you changed your password and you still think that someone have the old wallet file, you should move bitcoins somewhere else.

william3489

newbie

Activity: 8

Merit: 0

What happens if I change my wallet password but somebody has a copy of my wallet that was made before I changed my password? Can they still spend my bitcoins with the old password and the old wallet copy?

Topic: Changing wallet password, what happens? (Read 1062 times)