Bitcoin Address Generation Question

[Reckman]

Well...I thought I had a pretty good handle on the protocol until today.

I have an old wallet that I have been using, I move it to a new computer ect to preserve my old addresses, but I was under the assumption that new receiving address's would have their own private public pair. This doesnt seem to be the case, my old wallets still have access to coins in new locations.


What is going on? how can I keep my old addresses and generate new secure addresses

[polarhei]

A user has asked me how to restore the current. I say, backup the wallet.dat first. Then kill the corrupt parts.

After the wiping, re-open the bitcoin client, close it.

Then put wallet.dat into the place, you know, .bitcoin on /home/<user>

reopen the client again You shall see the address is back.

The user does not know if it is returned into normal state.

[BurtW]

Well...I thought I had a pretty good handle on the protocol until today.

I have an old wallet that I have been using, I move it to a new computer ect to preserve my old addresses, but I was under the assumption that new receiving address's would have their own private public pair. This doesnt seem to be the case, my old wallets still have access to coins in new locations.


What is going on? how can I keep my old addresses and generate new secure addresses

What wallets are you using?

A user has asked me how to restore the current. I say, backup the wallet.dat first. Then kill the corrupt parts.

After the wiping, re-open the bitcoin client, close it.

Then put wallet.dat into the place, you know, .bitcoin on /home/<user>

reopen the client again You shall see the address is back.

The user does not know if it is returned into normal state.

Not sure what you are talking about.

[Reckman]

Standard QT Client 0.8.5

[BurtW]

Standard QT Client 0.8.5

So, let me get this straight:

1) You had a wallet, used it, created a few addresses, have BTC etc.

2) You then moved the wallet.dat file to a different computer.

3) You found you had all the BTC you had before - so all was good.

4) On the new wallet you created a few more addresses and sent money to them.

5) You then went back to the original wallet and found that the new addresses you had created on the new wallet magically appeard in the old wallet!

Is that correct?

[Reckman]

Ya thats right.

I also noticed alot of times when I make a new address it has already been used, are all of the addresses in a wallet just made with the same private key?

So if I took the same wallet and took it to two computers and made 10 addresses would they be the same?

[BurtW]

Ya thats right.

I also noticed alot of times when I make a new address it has already been used, are all of the addresses in a wallet just made with the same private key?

So if I took the same wallet and took it to two computers and made 10 addresses would they be the same?

By design the next 100 key pairs are pre generated.

This is on purpose so the following works:

1) back up your wallet
2) go a "while" using your wallet, create a few new addresses, get some BTC sent to you etc.
3) CRASH - OH NO!
4) recover wallet.dat from back up

As long as you did not burn through the 100 pre generated addresses you are totally OK.

Cool, eh?

[Reckman]

Ah That makes sense, guess I just need to make a new wallet and import my old keys.


Thanks

[BurtW]

To answer your other question:

Every single Bitcoin address (starts with a 1 followed by a bunch of letters and numbers) is a special hash of the public key of a unique private/public key pair.  The sequence goes like this:

1) Create a private key (random number)

2) From the private key calculate the public key (actually a point on a curve so it has an X and a Y coordinate)

3) From the public key calculate the Bitcoin address (three hashes and a checksum)

Let me know if you have any more questions!