Why is my bitcoin client creating new addresses?

[xtoro]

Like the subject states, everytime I start up the bitcoin client, I have a new bitcoin address.  If I click on the addresses button, I can still see all my old ones including my original one, but it creates a new one everytime I start it up.

Is this normal?  I have 5 addresses now but I'm only using one!  I don't want any more addresses!

Running on Windows 7.

 

[wumpus]

It automatically creates a new address when receiving coins on your last-created address.

This is indeed very un-intuitive, and I've removed this for the new UI.

[xtoro]

So this is normal?  Should I upgrade the client?  I just don't want to eventually end up with 1000 addresses...

EDIT : Nevermind.  I see your client is for linux... like I said in the OP, I'm running Win7

[MtRev]

There a new version of the client that removes this issue?

[wumpus]

EDIT : Nevermind.  I see your client is for linux... like I said in the OP, I'm running Win7

It is windows as well as linux, but it is not integrated into the mainline yet. It is still a work in progress.

What I did was competely remove the "default address" functionality, as it doesn't really do anything beyond confuse users. It now simply shows you a list of addresses on which you can receive coins.

[Noam]

[/quote]
It is windows as well as linux, but it is not integrated into the mainline yet. It is still a work in progress.

What I did was competely remove the "default address" functionality, as it doesn't really do anything beyond confuse users. It now simply shows you a list of addresses on which you can receive coins.
[/quote]

Sounds like a nice improvement to the addresses UI
Did you decide to do that on your own? Or as a response to user requests?

[error]

There a new version of the client that removes this issue?

It's not an issue, per se. Bitcoin tries to keep a pool of 100 addresses in reserve for your future use. Whenever one address receives coins, a new one is displayed. This is so that, by default, people will use new addresses for every transaction, and only reuse addresses when absolutely necessary.

Now, the UI for address handling needs a LOT of improvement. But the basic functionality probably isn't going to change; using new addresses helps keep you safe, not to mention helps you determine who you got coins from. Or at least that's the idea. There have been detailed discussions of this in the past, though I don't have them at hand. You might find them from a search.

[wumpus]

Sounds like a nice improvement to the addresses UI
Did you decide to do that on your own? Or as a response to user requests?

In response to user requests.

The underlying basic functionality will not change. You're still encouraged to make new addresses for receiving payments for different people (if only for your own accounting/labeling, or for privacy, doesn't matter), but it doesn't automatically create unlabeled addresses anymore.

[Rob P.]

I've also found that people don't understand how transactions work:

All address must use their balances in full.  So, if you have one address with 0.5 BTC and another with 0.6 BTC and you send 1.0 BTC to someone then there is 0.1 BTC "change".  Since the inputs have to be used in full, the client will automatically create a new address and send the 0.1 BTC to that address.

When you look at the transaction in Block Explorer, you'll see 2 inputs (the 0.5 BTC and the 0.6 BTC addresses) and two outputs (the recipient of the 1.0 BTC, and a newly created address in your wallet.dat to receive the 0.1 BTC).

So, it looks like Bitcoin is just creating addresses constantly for no reason.  The reality is that it's part of the protocol.

[elggawf]

So, it looks like Bitcoin is just creating addresses constantly for no reason.  The reality is that it's part of the protocol.

Is there a technical/protocol reason the client can't just sign the change back to the same address? The inputs and outputs must be different?

[TheBitMan]

Can someone tell me how to back my wallet up please?

[lettucebee]

It automatically creates a new address when receiving coins on your last-created address.

This is indeed very un-intuitive, and I've removed this for the new UI.

Ah, nice. Thank you, John Smith!

[geek-trader]

It's not an issue, per se. Bitcoin tries to keep a pool of 100 addresses in reserve for your future use. Whenever one address receives coins, a new one is displayed. This is so that, by default, people will use new addresses for every transaction, and only reuse addresses when absolutely necessary.

I never understood why this is encouraged.

[Rob P.]

Can someone tell me how to back my wallet up please?

cp wallet.dat wallet.bak

[Rob P.]

So, it looks like Bitcoin is just creating addresses constantly for no reason.  The reality is that it's part of the protocol.

Is there a technical/protocol reason the client can't just sign the change back to the same address? The inputs and outputs must be different?

Yes.

From:  https://en.bitcoin.it/wiki/Transactions

There can be more than one output, and they share the combined value of the inputs. Because an output can only ever be referenced by a single input, the entire combined input value needs to be sent in an output if you don't want to lose it. If the input is worth 50 BTC but you only want to send 25 BTC, Bitcoin will create two outputs worth 25 BTC: one to the destination, and one back to you (known as "change", though you send it to yourself). Any input bitcoins not redeemed in an output is considered a transaction fee; whoever generates the block will get it.