<blockquote>
  <p>Why is there bitcoin address in the transaction, when the bitcoin script already contains the pubkey hash?</p>
</blockquote>

<p>Contrary to popular belief, this is not true. Addresses are not part of transactions at all, nor are they part of the protocol. The address is only used to encode the pubkey hash or script hash which is then used to create the output script.</p>

<blockquote>
  <p>Why isn't the amount a part of the script?</p>
</blockquote>

<p>It does not need to be. The script is a program, it does not care about the amount.</p>

<blockquote>
  <p>Why does bitcoin script allow to sign only parts of the transaction?</p>
</blockquote>

<p>To allow for special transactions where only part of the transaction needs to be signed. This allows people to do things like anyone-can-pay transactions or for people to sign only for specific outputs created by the transaction.</p>

CC BY-SA 3.0
2018-01-16T20:24:57.567Z
But why isn't the amount signed?
Michael Kruglos
CC BY-SA 3.0
2018-01-16T20:30:04.630Z
The amount is signed. It's part of the transaction and the whole transaction except for the signatures themselves is signed.
Ava Chow
CC BY-SA 3.0
2018-01-16T20:13:47.010Z
2018-01-16T20:13:47.010Z
Ava Chow
<p>Can someone clarify?</p>

<ul>
<li>Why is there bitcoin address in the transaction, when the bitcoin script already contains the pubkey hash?</li>
<li>Why isn't the amount a part of the script?</li>
<li>Why does bitcoin script allow to sign only parts of the transaction? </li>
</ul>

CC BY-SA 3.0
2018-01-16T20:36:52.763Z
Looking at the type of questions, one might come to the conclusion, that you have ideas behind, that are not stated. Is the“why“ just a statement for wanting to know? I feel like you seem to see additional value, if the amount would be part of the script, or the whole tax would be signed... ?
pebwindkraft
<transactions><transaction-verification>
How bitcoin transaction fromat design can be explained?
Michael Kruglos
# How bitcoin transaction fromat design can be explained?

(Asked by: username_0 on 2018-01-16)

Can someone clarify?

* Why is there bitcoin address in the transaction, when the bitcoin script already contains the pubkey hash?
* Why isn't the amount a part of the script?
* Why does bitcoin script allow to sign only parts of the transaction?

**Tags:** transactions, transaction-verification

> **Comments:**
> **username_1**: Looking at the type of questions, one might come to the conclusion, that you have ideas behind, that are not stated. Is the“why“ just a statement for wanting to know? I feel like you seem to see additional value, if the amount would be part of the script, or the whole tax would be signed... ?  

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## 1 answers

### Answer by username_2 on 2018-01-16. Score: 1

> Why is there bitcoin address in the transaction, when the bitcoin script already contains the pubkey hash?

Contrary to popular belief, this is not true. Addresses are not part of transactions at all, nor are they part of the protocol. The address is only used to encode the pubkey hash or script hash which is then used to create the output script.

> Why isn't the amount a part of the script?

It does not need to be. The script is a program, it does not care about the amount.

> Why does bitcoin script allow to sign only parts of the transaction?

To allow for special transactions where only part of the transaction needs to be signed. This allows people to do things like anyone-can-pay transactions or for people to sign only for specific outputs created by the transaction.

> **Comments:**
> **username_0**: But why isn't the amount signed?  
> **username_2**: The amount is signed. It's part of the transaction and the whole transaction except for the signatures themselves is signed.  

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