Bitcoin Forum

Hi

what happen if i send coins to offline address or a addres that doesn't exists?

If you send coins to a valid address, the blockchain will record that address as having those coins until they are spent by someone with a keypair that matches that address.  Realisticly speaking, if you send coins to a valid address that has no real owner, they will sit in the blockchain for much longer than our natural lifetimes and cannot be recovered by anyone, even if you can prove that you own them.  If you send coins to someone who is offline, the blockchain doesn't care that they are not online, and their client will see the new transactions the next time that they are online.

Offline: no problem, they now have access to the coins whenever they want

Invalid: the client won't send them.

Valid, but no one has the key: lost forever

A typo won't lose coins because there is a checksum to test validity, multiple very unlucky typos could lose coins though.

Ooh, so someone could attack the network by generating coins and posting them to deliberately broken addresses?

That would be a self attack, we don't need all 21M coins. 2M or even .02 total coins would be fine.

The attacker would require a lot of computer power to generate the vast majority of remaining bitcoins. It seems like an unlikely scenario.

One of my friends (well, a friend of a friend) runs code on racks of servers containing boards which host masses of GPUs for fluid dynamics calculations for the oil industry, not sure how much these systems cost, but they are available to industry and are as powerful as several thousand high end graphics cards.

Banks could easily afford them

Wait, computer power can be bought in bulk? This changes everything.  ::)

So, the evil banks invest in super computers just to horde bitcoins? Where's the profit in that?

That would be no more damaging to the network than someone just generating coins and keeping them.

It would be comparable to someone buying gold and launching it into the Sun.  It would make the remaining gold more valuable while making the rich idiot less rich.  Not only would that not harm the bitcoin economy in any way, it would actually improve the blockchain security for as long as the wealthy idiot could keep it up.

lets say that i change last number in the address for example form 6 to 7 accidentally, the address will be valid.
and then send all my savings to this nonexisting address, i am broke because of one small mistake.

correct,
that's how cash works, if you give all your fiat-paper-money to some random guy on the streets, your broke too, cuz you did (by mistake or not).

the only little difference is, that the random guy will be quite happy to have some more cash,
with a valid but non-existant btc-address the cash is just lost in space,
but i guess that doesnt matter on your side.

No, the address won't be valid anymore, there's a built-in checksum

ahh, yes true, shame one me.   :D
just tried it and it didnt work.

I did say this in the post you quoted:

A typo won't lose coins because there is a checksum to test validity, multiple very unlucky typos could lose coins though.

The typo I'm worried about is when I omit the dot and send 1234 coins instead of the 12.34 that I meant to send.

Yeah, that could happen. It might be bad, but not as bad as going to a non existent address. In many cases you will have contact with the person you are paying and can get it back.

Eventually someone will probably create a warning add-on that makes you click again when you send above a certain fixed amount or above 10x your average send or something like that.

Yea but that has nothing to do with bitcoin

That would be nice. It will protect me from when the cat sits on the keyboard and accidentally sends all of my BTC. Or from when I think I'm connected to the test network and I'm really connected to the main network.