<p>Because an address <strong>is</strong> the Hash160 (=RIPEMD160(SHA256(x))) of the public key. The transaction output lists that 160-bit hash directly.</p>

<p>When redeeming such an output, you provide both the public key (which must hash to the value given in the output) and a signature (which must be valid for the given public key).</p>

CC BY-SA 3.0
2013-03-08T04:02:42.487Z
i'm used to seeing hash algos referred to as SHA256 or RIPEMD.  what is Hash160?
joe
CC BY-SA 3.0
2013-03-08T11:19:29.263Z
@joe `Hash160 = RIPEMD160(SHA256(m))` (note that plain RIPEMD is a different, broken hash and bitcoin doesn't use it)
CodesInChaos
CC BY-SA 3.0
2013-03-10T16:13:58.360Z
Edited. In Bitcoin-speak, Hash(x) = SHA256(SHA256(x)) and Hash160(x) = RIPEMD160(SHA256(x)).
Pieter Wuille
CC BY-SA 3.0
2013-03-16T15:43:20.610Z
as a related question, what is really stored in a wallet in regards to keys?  just the priv keys or priv keys and pub keys?  i ask since the pub keys can be derived from the priv keys.
joe
CC BY-SA 3.0
2015-03-24T23:27:39.207Z
The Public Key Hash is equivalent to the bitcoin address, without the Base58Check encoding.
 RIPEMD160(SHA256(PubK)) == Base58.decode(Address) ?
Haddar Macdasi
CC BY-SA 3.0
2013-03-08T00:00:16.957Z
2013-03-10T16:13:16.957Z
2013-03-10T16:13:16.957Z
Pieter Wuille
<p>I was looking thru Block explorer at an address with a balance.  It has never been spent from thus the public key is unknown.  If the public key is unknown, how can Block explorer calculate the hash160 of the public key?</p>

<transactions>
How is hash160 calculated from an unseen public key?
joe
# How is hash160 calculated from an unseen public key?

(Asked by: username_0 on 2013-03-07)

I was looking thru Block explorer at an address with a balance. It has never been spent from thus the public key is unknown. If the public key is unknown, how can Block explorer calculate the hash160 of the public key?

**Tags:** transactions


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## 1 answers

### Answer by username_1 on 2013-03-08. Score: 9

Because an address **is** the Hash160 (=RIPEMD160(SHA256(x))) of the public key. The transaction output lists that 160-bit hash directly.

When redeeming such an output, you provide both the public key (which must hash to the value given in the output) and a signature (which must be valid for the given public key).

> **Comments:**
> **username_0**: i'm used to seeing hash algos referred to as SHA256 or RIPEMD.  what is Hash160?  
> **username_2**: @username_0 `Hash160 = RIPEMD160(SHA256(m))` (note that plain RIPEMD is a different, broken hash and bitcoin doesn't use it)  
> **username_1**: Edited. In Bitcoin-speak, Hash(x) = SHA256(SHA256(x)) and Hash160(x) = RIPEMD160(SHA256(x)).  
> **username_0**: as a related question, what is really stored in a wallet in regards to keys?  just the priv keys or priv keys and pub keys?  i ask since the pub keys can be derived from the priv keys.  
> **username_3**: The Public Key Hash is equivalent to the bitcoin address, without the Base58Check encoding.  RIPEMD160(SHA256(PubK)) == Base58.decode(Address) ?  

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