<p>It only knows anything about the address because you asked about it.</p>

<p>Since the address has never appeared in the blockchain, all it knows is <a href="https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses">what can be seen</a> from the address: its hash160 value. This is the hexadecimal version of what is encoded in your address, which is a hash of your public key via the <a href="https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses">algorithm explained here</a>.</p>

CC BY-SA 3.0
2014-05-02T17:56:49.427Z
okey, but if I change last two letters in address: 1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe -> 1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1eF . Blockchain.info doest't know about it, but it also address or not?
user3473712
CC BY-SA 3.0
2014-05-02T17:58:49.550Z
An address includes a 32-bit checksum. If you carelessly change some portion of the address, the new address will most likely be invalid. Blockchain.info recognizes this and rejects it.
Tim S.
CC BY-SA 3.0
2014-05-02T17:43:20.577Z
2014-05-02T17:43:20.577Z
Tim S.
<p>I generate new address in client. I hear that blockchain doesn't know about it. Blockchain will know about it when I use this address for transaction.</p>

<p>My example:
I generate this address(offline): 1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe
I haven't used yet. How does website blockchain.info know about my address??? <a href="https://blockchain.info/address/1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe" rel="nofollow">https://blockchain.info/address/1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe</a> </p>

<address><public-key><address-generation>
Genenerate address offline, but blockchain knows about my address
user3473712
# Genenerate address offline, but blockchain knows about my address

(Asked by: username_0 on 2014-05-02)

I generate new address in client. I hear that blockchain doesn't know about it. Blockchain will know about it when I use this address for transaction.

My example:
I generate this address(offline): 1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe
I haven't used yet. How does website blockchain.info know about my address??? <https://blockchain.info/address/1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe>

**Tags:** address, public-key, address-generation


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## 1 answers

### Answer by username_1 on 2014-05-02. Score: 6 | Accepted answer

It only knows anything about the address because you asked about it.

Since the address has never appeared in the blockchain, all it knows is [what can be seen](https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses) from the address: its hash160 value. This is the hexadecimal version of what is encoded in your address, which is a hash of your public key via the [algorithm explained here](https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses).

> **Comments:**
> **username_0**: okey, but if I change last two letters in address: 1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1Fe -> 1J1JqUPqKq4XvrDRioMSMYKrwL3wKdJ1eF . Blockchain.info doest't know about it, but it also address or not?  
> **username_1**: An address includes a 32-bit checksum. If you carelessly change some portion of the address, the new address will most likely be invalid. Blockchain.info recognizes this and rejects it.  

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