Sending Bitcoins to an offline address.

[dE_logics]

If I send Bitcoins to an address which's offline what will happen?

As per my understanding, sending Bitcoins to an offline or non-existing address will not eat up my balance cause the receiving address needs to be broadcasted by the receiver and that broadcast needs to be recorded in the block chain, since the receiver is offline, this broadcast wont happen.

So if I rescan my wallet, I should get my Bitcoins back.

[1715602877]

1715602877

[1715602877]

1715602877

[shorena]

If I send Bitcoins to an address which's offline what will happen?

There are no offline addresses.

As per my understanding, sending Bitcoins to an offline or non-existing address

There are no valid non-existing address. You can either make a valid transaction and send the coins because the address is possible or you cant make a transaction at all.
There are certainly addresses that no belonging private key exists for yet. If you send coins to such an address they will be lost forever.

will not eat up my balance cause the receiving address needs to be broadcasted by the receiver and that broadcast needs to be recorded in the block chain, since the receiver is offline, this broadcast wont happen.

No, you just make a valid transaction (you can spend the former input as a new output = you have the private key to spend the funds) for a possible reiceiving address. You then broadcast that TX. Validity is checked, but that does not include a check whether the private key for the receiving address has yet been created. A check like that is not possible anyway. After a while the TX gets included in the next block and the coins are no longer yours.

It is possible that the coins now belong to noone.

So if I rescan my wallet, I should get my Bitcoins back.

No, they are gone.

Edited to to avoid confusion

[DeathAndTaxes]

As per my understanding, sending Bitcoins to an offline or non-existing address will not eat up my balance cause the receiving address needs to be broadcasted by the receiver and that broadcast needs to be recorded in the block chain, since the receiver is offline, this broadcast wont happen.

That is not correct.

There is no such thing as broadcasting a receiving address.  A transaction is simply a signed message that transferring value to a new identity.  There is no such thing as online or offline addresses.

Although we use terms like "transferring bitcoins to address x" they are just abstractions which fit our expectation of how money works.  You don't send coins to someone you record an instruction in the blockchain.  Transactions "spend" or destroy existing outputs by referring to them in the input side of the tx and create new outputs in the output side of the tx.  When that tx or instruction is recorded in the blockchain your "balance" is reduced because the output you had which was previously unspent is now spent.   You aren't sending anything to a particular online computer you are broadcasting that instruction to every node on the network.

A nice effect of this system is you don't need a wallet to be "online" in order to "receive" funds.

[dE_logics]

What I didn't know was that the miners do the verification of the transactions -- that was the missing link. Thanks!

[dE_logics]

Just one more question -- how much computation power is required to verify transactions?

And more importantly -- doesn't this need a lot of disk i/o?

[shorena]

Just one more question -- how much computation power is required to verify transactions?

The verification is the easy part. The hard part is to find a block to put the TX in. Well if thats hard depends on the difficulty.

And more importantly -- doesn't this need a lot of disk i/o?

No, the last blocks just had a few KB in size

62 KB https://blockchain.info/block-index/435023/00000000000000005077bb73156f2d8efb26a64ca0ab46ab7bb632c1c994c7c7
319 KB https://blockchain.info/block-index/435022/000000000000000009d35810ba51943841bb8123d3611be56209194bd1a069bc
91 KB https://blockchain.info/block-index/435021/000000000000000047afcea8bd87cc842b37c843b1e5643455a9f24d3b291700

IIRC the current limit on size per block is 1 MB. Thats easily stored in RAM

[dE_logics]

Just one more question -- how much computation power is required to verify transactions?

The verification is the easy part. The hard part is to find a block to put the TX in. Well if thats hard depends on the difficulty.

And more importantly -- doesn't this need a lot of disk i/o?

No, the last blocks just had a few KB in size

62 KB https://blockchain.info/block-index/435023/00000000000000005077bb73156f2d8efb26a64ca0ab46ab7bb632c1c994c7c7
319 KB https://blockchain.info/block-index/435022/000000000000000009d35810ba51943841bb8123d3611be56209194bd1a069bc
91 KB https://blockchain.info/block-index/435021/000000000000000047afcea8bd87cc842b37c843b1e5643455a9f24d3b291700

IIRC the current limit on size per block is 1 MB. Thats easily stored in RAM

Actually I was more concerned about the seek times. Suppose the input refers to an old transaction that has to be searched in the block chain, which should take quiet a lot of CPU and more importantly disk i/o.

[DeathAndTaxes]

Clients maintain a database of just the unspent outputs (UTXO) as only unspent outputs can be inputs for new txs.  This is ~800MB.  The raw blocks from the blockchain are not used in the verification of new txs.

[dE_logics]

Clients maintain a database of just the unspent outputs (UTXO) as only unspent outputs can be inputs for new txs.  This is ~800MB.  The raw blocks from the blockchain are not used in the verification of new txs.

Thanks for verifying that.

[DannyHamilton]

There are certainly addresses that no belonging private key exists for yet. If you send coins to such an address - I wonder how you got it, but lets just say you somehow managed that - Someone in the future generating that private key will be very happy.

Please don't spread nonsense like this.  It tends to confuse the newbies.

[ranochigo]

If I send Bitcoins to an address which's offline what will happen?

As per my understanding, sending Bitcoins to an offline or non-existing address will not eat up my balance cause the receiving address needs to be broadcasted by the receiver and that broadcast needs to be recorded in the block chain, since the receiver is offline, this broadcast wont happen.

So if I rescan my wallet, I should get my Bitcoins back.

It will be broadcasted in the Bitcoin network. Your BTC isn't stored within your private key and the transaction is broadcasted to the whole network.  The receiving address can be generated offline and the coins will still be sent to the address, as long as the address is valid.