Bitcoin Forum

Bitcoin => Armory => Topic started by: dadach on November 21, 2013, 08:21:12 AM



Title: change-back-to-self address
Post by: dadach on November 21, 2013, 08:21:12 AM
the client created one. why did it do it, and how does it work?

tnx


Title: Re: change-back-to-self address
Post by: etotheipi on November 21, 2013, 04:46:07 PM
When you go to a store and try to pay for your candy bar with a $20-bill, the cashier takes your $2.29 and gives you $17.71 change.  This is the same thing: your outgoing transactions have to combine multple previous transactions (bills) to pay the target amount, but frequently overshoot.  For instance, when you try to pay for 0.1 BTC, you might have to use a 3 BTC input to construct the transaction, then you'd actually create two outputs fro the tx:  0.1 to the target recipient, and 2.9 back to yourself. 

Armory creates a new address in your wallet (always protected by your paper backup) for these change outputs.  It marks them with that comment so that you know you didn't create that address yourself.  All of them are still part of your wallet and [most importantly] are still protected by your paper backup.  It's just a quirk in the way the Bitcoin transactions work.