<p>This is from their FAQ.</p>

<p>Bitcoin Cash transactions use a new flag SIGHASH_FORKID, which is non standard to the legacy blockchain.  This prevents Bitcoin Cash transactions from being replayed on the Bitcoin blockchain and vice versa.</p>

CC BY-SA 3.0
2017-08-02T13:13:24.310Z
I'm not talking about replaying a transaction. What I ask is what would happen if someone creates two different transactions for two different blockchains, using the same private key.
yozel
CC BY-SA 3.0
2017-08-02T14:02:43.337Z
Then I don't understand your question
Pieter Wuille
CC BY-SA 3.0
2017-08-02T13:03:01.213Z
2017-08-02T13:03:01.213Z
m1xolyd1an
<p><code>    ------X--.---------- BTC Blockchain
              \
               .--------- BCC Blockchain</code></p>

<p>Let's say that we have some BTC coins from a transaction at block X. And, there are two blockchains now. Is spending these coins at both blockcoins prevented? Are there any BTC/BCC cross check for double spending?</p>

<blockchain><doublespend><bitcoin-cash>
How spending same coins both at BCC and BTC blockchains prevented?
yozel
# How spending same coins both at BCC and BTC blockchains prevented?

(Asked by: username_0 on 2017-08-02)

`------X--.---------- BTC Blockchain
\
.--------- BCC Blockchain`

Let's say that we have some BTC coins from a transaction at block X. And, there are two blockchains now. Is spending these coins at both blockcoins prevented? Are there any BTC/BCC cross check for double spending?

**Tags:** blockchain, doublespend, bitcoin-cash


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## 1 answers

### Answer by username_1 on 2017-08-02. Score: 0

This is from their FAQ.

Bitcoin Cash transactions use a new flag SIGHASH\_FORKID, which is non standard to the legacy blockchain. This prevents Bitcoin Cash transactions from being replayed on the Bitcoin blockchain and vice versa.

> **Comments:**
> **username_0**: I'm not talking about replaying a transaction. What I ask is what would happen if someone creates two different transactions for two different blockchains, using the same private key.  
> **username_2**: Then I don't understand your question  

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