<p>Owner #1's signature is required for Transaction #2 because Owner #1 at that point owns the bitcoin. It's being signed over to Owner #2.</p>

<p>Think of it this way, who signs a USD check where money goes from #1 to #2? It's always whoever owns the money beforehand.</p>

CC BY-SA 3.0
2016-08-08T14:41:07.700Z
2016-08-08T14:41:07.700Z
Jimmy Song
<p><img src="https://i.sstatic.net/WMsU6.png" alt="Chain of transactions"></p>

<p>In Bitcoin, what is the <em>Signature</em> and why <em>Owner 1's Signature</em> is in transaction #2, not #1?</p>

<p>I'm implementing a demonstration of blockchain database. But I noticed that the Bitcoin whitepaper has many ambiguous things, such as what is a hash of previous transaction of the first transaction. But the hash problem seems to be resolved somehow. The problem is what is the signatures and why it exists in next transaction of its owner issued?</p>

<blockchain>
Why Owner 1's Signature is in transaction #2, not #1
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# Why Owner 1's Signature is in transaction #2, not #1

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

![Chain of transactions](https://i.sstatic.net/WMsU6.png)

In Bitcoin, what is the *Signature* and why *Owner 1's Signature* is in transaction #2, not #1?

I'm implementing a demonstration of blockchain database. But I noticed that the Bitcoin whitepaper has many ambiguous things, such as what is a hash of previous transaction of the first transaction. But the hash problem seems to be resolved somehow. The problem is what is the signatures and why it exists in next transaction of its owner issued?

**Tags:** blockchain


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## 1 answers

### Answer by username_1 on 2016-08-08. Score: 2 | Accepted answer

Owner #1's signature is required for Transaction #2 because Owner #1 at that point owns the bitcoin. It's being signed over to Owner #2.

Think of it this way, who signs a USD check where money goes from #1 to #2? It's always whoever owns the money beforehand.


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