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Topic: Bitcoin Address creation (Read 1121 times)

cp1
hero member
Activity: 616
Merit: 500
Stop using branwallets
April 25, 2013, 11:46:04 PM
#11
You don't create the address.  You just randomly generate a private key and use the corresponding public key as your address.  Imagine a wall of PO boxes with a huge bucket of keys.  You grab a key and then you get to use the PO box that it unlocks.  There's just so many PO boxes that the chances of any person randomly choosing your key in the bucket is really small.
legendary
Activity: 3472
Merit: 4801
April 25, 2013, 11:19:31 PM
#10
Quote
Then you can safely assume that any bitcoins that are sent to that address will be "stuck" at that address and remain unspendable forever.
until someone has by chance generated that address - i guess

As I said:

- snip -
The odds of two people who generate random addresses actually generating the same address are not just "astronomically unlikely", it is beyond "astronomical".  For all intents and purposes, you can just assume that it's impossible.
- snip -
full member
Activity: 126
Merit: 100
April 25, 2013, 06:57:50 PM
#9
Quote
Then you can safely assume that any bitcoins that are sent to that address will be "stuck" at that address and remain unspendable forever.
until someone has by chance generated that address - i guess
legendary
Activity: 3472
Merit: 4801
April 25, 2013, 10:30:17 AM
#8
If I create another Bitcoin address in my wallet, how can I be sure that this address has not been created by someone else?

Probability.  The odds of two people who generate random addresses actually generating the same address are not just "astronomically unlikely", it is beyond "astronomical".  For all intents and purposes, you can just assume that it's impossible.

I mean, creating a new address seems instant, what if someone else also has created the same address at around the same time.
What is going to happen then?

It is nearly instant.  Your wallet just chooses a random number for the Private Key, and then quickly does some Elliptic Curve multiplication to generate the Public Key.  A few quick SHA-256 and RIPEMD-160 hashes later and you've got a Bitcoin Address.

Nobody is going to randomly choose the same address.  It just isn't going to happen.

But for the sake of argument...

If it did happen, then you both would receive any bitcoins sent to that address, and you both could spend those bitcoins.  If the other person spent them, they would disappear out of your wallet.
legendary
Activity: 3472
Merit: 4801
April 25, 2013, 10:26:32 AM
#7
And what happens if
a) I send coins to an address that does not exist?
b) I send coins to an address that does not exist, but will be created e.g. 4 months later?

It depends on what you mean by "does not exist".

Bitcoin Addresses have a checksum built into them.  It is nearly impossible to make a typo and end up with an address that a wallet will accept as a valid address.

On the other hand, if you intentionally create an address with the proper formatting and checksum, without knowing the private key for that address.  Then you can safely assume that any bitcoins that are sent to that address will be "stuck" at that address and remain unspendable forever.
newbie
Activity: 46
Merit: 0
April 25, 2013, 09:20:30 AM
#6
All the addresses "exist". You will find it difficult to spend the coins without an associated private key, though.
full member
Activity: 126
Merit: 100
April 25, 2013, 08:45:45 AM
#5
And what happens if
a) I send coins to an address that does not exist?
b) I send coins to an address that does not exist, but will be created e.g. 4 months later?
legendary
Activity: 1652
Merit: 1016
April 25, 2013, 08:44:27 AM
#4
A thanks for the thread.

Btw, the address creation feels so fast, like a fraction of a second.
How does the network know that the just created address belongs to my wallet?
Is there somewhere I can see that?

The network doesn't know about it until some coins are sent to it.
full member
Activity: 126
Merit: 100
April 25, 2013, 08:37:48 AM
#3
A thanks for the thread.

Btw, the address creation feels so fast, like a fraction of a second.
How does the network know that the just created address belongs to my wallet?
Is there somewhere I can see that?
legendary
Activity: 1610
Merit: 1004
April 25, 2013, 08:26:56 AM
#2
You could check the address at blockchain.info

It is highly unlikely you will ever have a collision, many threads already here discussing this

see: https://bitcointalksearch.org/topic/bitcoin-address-collisions-62
full member
Activity: 126
Merit: 100
April 25, 2013, 08:22:31 AM
#1
If I create another Bitcoin address in my wallet, how can I be sure that this address has not been created by someone else?
I mean, creating a new address seems instant, what if someone else also has created the same address at around the same time.
What is going to happen then?
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