Bitcoin Signer Error: Witness Hash Mismatch
As a Bitcoin developer, you have probably encountered problems when trying to sign transactions with private keys on your local machine. A common error is the witness hash mismatch issue, which prevents your script from properly verifying and signing transactions.
In this article, we will go into the details of the issue and provide a step-by-step guide to resolving it.
Problem
When you try to sign a raw transaction with your private key on Bitcoin Core (BTC testnet) using Regtest, you may encounter the following error:
witness hash mismatch
This error typically occurs when the script cannot verify that the witness hash matches the expected value in the transaction. This can have various causes, such as:
- Incorrect or missing script hashes
- Inadequate private key setup
- Invalid or corrupted transactions
- Script errors or syntax issues
Troubleshooting steps
To resolve this issue and fix the witness hash mismatch error, follow these steps:
1. Check your private key setup
Make sure your private key is set up correctly in Bitcoin Core. Here are a few things to check:
- Make sure you have installed the “bitcoin-qt” package and confirmed its installation.
- Make sure your private key file (usually stored at $HOME/.Bitcoin/privkey.json) contains valid script hashes for all scripts, including the transaction you want to sign.
2. Check transaction details
Gather additional information about the transaction you want to sign:
- Transaction details: Check that the transaction hash is correct and matches the expected value.
- Debug script: Run your script with the « –debug » flag to get detailed output that can help identify problems.
Example command:
bitcoin-qt --regtest -txindex --debug -o myscript tx
3. Check witness hashes
Check that the witness hashes are correct for all scripts in your script:
- Get script hashes
: Run « bitcoin-qt –list-scripts » to list all scripts with their corresponding hashes.
- Check script hashes: Check that the script hash of each script matches the expected value.
Example command:
bitcoin-qt --regtest -txindex --debug -o myscript tx
4. Run the script with debug output
Run your script with the --debug flag to generate detailed debug output:
* bitcoin-qt –regtest -txindex –debug -o myscript tx
This will display a detailed list of transactions, including their hashes and the scripts used.
5. Update the script (optional)
If you suspect that the script itself is incorrect or outdated, update your script to ensure that it matches the latest available version:
- Update the script: Rungit pull` or use a package manager such as pip to update your script to the latest version.
Example:
git clone
cd scripthash
git checkout
6. Rerun the script with the corrected script hashes
After you have fixed any issues with the script hashes, rerun the script to verify that it produces the correct transaction output.
Conclusion
In this article, we have walked you through the steps to fix the « Witness program hash mismatch » error in Bitcoin Core while signing transactions with private keys. By checking your private key settings, checking the transaction details, checking the witness program hashes, running the scripts with debug output, updating the scripts (if necessary), and rerunning the scripts with the correct script hashes, you should be able to resolve this issue and successfully sign raw transactions with Regtest.
