Bitcoin Forum

Hello,

I am new with Bitcoin. I noticed when I transfer Bitcoins, there is everytime a secondary transaction to unknown Bitcoin address in the blockchain (marked with green in the screenshot). Could someone understand what is that?

Screenshot: http://imageshack.us/photo/my-images/37/bitcoin.png/ (http://imageshack.us/photo/my-images/37/bitcoin.png/)

Thank you!

That is the address where your spare change is sent to. (I'm guessing you sent the 1.13 transaction right?) It's an unpublished address generated inside your bitcoin client, which your wallet holds the keys to.

Thank you very much for your reply! That is correct! So I guess this means there is nothing I should be concerned about this?! :)

That is correct, as this will not affect the total amount of coins left in your wallet or anything. You can forcibly ask the remaining coins to be sent to the original address by using an alternative client like Electrum or blockchain.info's online wallet.
Glad to have helped ya. :D

You might be interested to know, for the benefit of your understanding of Bitcoin, as you've censored part of your addresses:

1 - censoring bitcoin addresses doesn't do any good, with just the first five or six chars we can know the whole address and see this same uncensored screen just by doing a search in blockchain.info
2 - censoring them doesn't do any harm (and is probably a good practice if you are unsure whether it's safe, seeing as how people have lost money leaving things in screenshots they shouldn't have, although bitcoin addresses weren't what they left showing)
3 - if anonymity were a concern, just knowing you did a recent transaction where the change was 1.13 would be enough to find your transaction on the block chain with a good deal of certainty.