<p><a href="https://i.sstatic.net/ke2y0.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ke2y0.png" alt="Byte-map of transaction"></a></p>

<p>See <a href="https://en.bitcoin.it/wiki/Transaction" rel="nofollow noreferrer">Bitcoin Wiki</a>.
Above image illustrates a byte-map of transaction with each type of TxIn and TxOut.</p>

<p>We should attention at "Coinbase/Generation" (Coinbase means the first transaction in a block).
Codebase's script is a arbitary data.
Yep, it is <strong>random</strong>.</p>

<p>Therefore the signature of first transaction of a block is not used.</p>

CC BY-SA 3.0
2016-08-14T23:47:22.610Z
2016-08-14T23:47:22.610Z
signal
<p><a href="https://i.sstatic.net/Ca4yF.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Ca4yF.png" alt="A chain of transactions"></a></p>

<p>In bitcoin, each transaction's signature is signed with previous owner's private key. Then, how sign the first transaction's signature?</p>

CC BY-SA 3.0
2016-08-14T22:33:20.487Z
related: [What is the coinbase?](http://bitcoin.stackexchange.com/q/4571/5406), [Where do bitcoins come from and what gives them their value?](http://bitcoin.stackexchange.com/q/182/5406)
Murch
<transactions><private-key><signature>
How sign the first transaction's signature?
signal
# How sign the first transaction's signature?

(Asked by: username_0 on 2016-08-14)

[![A chain of transactions](https://i.sstatic.net/Ca4yF.png)](https://i.sstatic.net/Ca4yF.png)

In bitcoin, each transaction's signature is signed with previous owner's private key. Then, how sign the first transaction's signature?

**Tags:** transactions, private-key, signature

> **Comments:**
> **username_1**: related: [What is the coinbase?](http://bitcoin.stackexchange.com/q/4571/5406), [Where do bitcoins come from and what gives them their value?](http://bitcoin.stackexchange.com/q/182/5406)  

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## 1 answers

### Answer by username_0 on 2016-08-14. Score: 0 | Accepted answer

[![Byte-map of transaction](https://i.sstatic.net/ke2y0.png)](https://i.sstatic.net/ke2y0.png)

See [Bitcoin Wiki](https://en.bitcoin.it/wiki/Transaction).
Above image illustrates a byte-map of transaction with each type of TxIn and TxOut.

We should attention at "Coinbase/Generation" (Coinbase means the first transaction in a block).
Codebase's script is a arbitary data.
Yep, it is **random**.

Therefore the signature of first transaction of a block is not used.


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