<p>Since A1 and A2 have the same public key, it means that the network will treat them as one person.</p>

CC BY-SA 3.0
2017-12-13T16:08:48.457Z
2017-12-13T16:08:48.457Z
philippinedev
<p>There can only be a single spend of a transaction output, it doesn't matter if there's multiple private keys which correspond to a script. It is functionally the same as one private key signing two transactions, they can't co-exist due to the consensus rules of Bitcoin.</p>

CC BY-SA 3.0
2017-12-07T07:06:35.370Z
2017-12-07T07:06:35.370Z
Claris
<p>Although statistically impossible, imagine that two different private keys share the same public key. Would that addresses be able to create new Bitcoins?
Let's say that private keys A1 and A2 have the same public key A. I use wallet B to send 1 Bitcoin to A. Both A1's and A2's wallets would show a 1 Bitcoin balance.
Now both A1 and A2 send 1 Bitcoin to B at approximately the same time. Will B now have 2 Bitcoins, or would one of the transactions fail?</p>

CC BY-SA 4.0
2021-08-22T02:57:06.977Z
To be exact, in ECC it is completely impossible for two distinct privatekeys to produce the same publickey. However nearly all Bitcoins (i.e. TXOs) are locked either to a script or to an **address** which is a 160-bit hash of a publickey (represented either in compressed or uncompressed form), not the actual publickey, so collision on an address _is_ theoretically possible, albeit much less likely than your brain spontaneously exploding.
dave_thompson_085
<wallet><private-key><public-key>
Can Bitcoins be duplicated if two private keys share the same public key?
Roee Anuar
# Can Bitcoins be duplicated if two private keys share the same public key?

(Asked by: username_0 on 2017-12-07)

Although statistically impossible, imagine that two different private keys share the same public key. Would that addresses be able to create new Bitcoins?
Let's say that private keys A1 and A2 have the same public key A. I use wallet B to send 1 Bitcoin to A. Both A1's and A2's wallets would show a 1 Bitcoin balance.
Now both A1 and A2 send 1 Bitcoin to B at approximately the same time. Will B now have 2 Bitcoins, or would one of the transactions fail?

**Tags:** wallet, private-key, public-key

> **Comments:**
> **username_1**: To be exact, in ECC it is completely impossible for two distinct privatekeys to produce the same publickey. However nearly all Bitcoins (i.e. TXOs) are locked either to a script or to an **address** which is a 160-bit hash of a publickey (represented either in compressed or uncompressed form), not the actual publickey, so collision on an address _is_ theoretically possible, albeit much less likely than your brain spontaneously exploding.  

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## 2 answers

### Answer by username_3 on 2017-12-07. Score: 4 | Accepted answer

There can only be a single spend of a transaction output, it doesn't matter if there's multiple private keys which correspond to a script. It is functionally the same as one private key signing two transactions, they can't co-exist due to the consensus rules of Bitcoin.


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### Answer by username_2 on 2017-12-13. Score: 0

Since A1 and A2 have the same public key, it means that the network will treat them as one person.


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