Converting Ethereum Cashdr (bech32) to the old Bitcoin Cash address format

Ethereum’s Cashaddr (bech32) has been adopted by some users as a convenient way to conduct transactions on the Ethereum network. However, this format is not directly compatible with old Bitcoin Cash wallets and blockchains. In this article, we will explore how to convert Bitcoin Cash-generated bech32 Ethereum addresses to their corresponding old Bitcoin Cash addresses.

What is bech32?

Bech32 is a standardized format used by several cryptocurrencies, including Ethereum. It was created as an alternative to Bitcoin’s traditional Merkle tree address system. Bech32 addresses are typically represented using the following template: “bitcoincash:q”, where “” is the Bitcoin Cash public key.

Legacy Bitcoin Cash Address Format

Legacy Bitcoin Cash addresses are usually in a different format that is not directly compatible with bech32. These formats often use a combination of characters and punctuation marks to indicate a Bitcoin Cash address. For example: “bc1…”. To convert bech32 to the old Bitcoin Cash address format, we will need to perform some additional conversions.

Converting Bech32 to Old Bitcoin Cash Address Format

To convert an Ethereum bech32 address to the old Bitcoin Cash address format, you can do the following:

• Uncomment the “q” prefix: remove the “q” from the beginning of the “bech32” address.

• Concatenate with the public key: add the public key to the resulting string.

Here is an example of the conversion process:

Let’s say we have an Ethereum bech32 address: “bitcoincash:q…”.

• Expand “q”: Remove the “q” prefix, leaving “bitcoca”.

• Merge with public key: Add the public key to the resulting string: bc1..., where ... is the random Bitcoin Cash private key.

The resulting old Bitcoin Cash address would be: “bc1…”.

Example use case

Let’s say you have an Ethereum wallet that generates bech32 addresses like this: “bitcoincash:q“. You can use this Python script to convert these addresses to their equivalent legacy Bitcoin Cash addresses:

in import
def bech32_to_legacy_bc(bech32_address):





Remove the 'q' prefix
q_prefix = bech32_address.startswith('q') and bech32_address[1:] or ''

Combine with the public key (assuming it is in the format "bc...")
legacy_bc_address = f"bc{re.findall(r'[0-9a-fA-F]{44}', q_prefix)[0]}"
return legacy_bc_address

Usage example
bech32_address = 'bitcoincash:q...'
legacy_bc_address = bech32_to_legacy_bc(bech32_address)
print(legacy_bc_address) 
Output: bc1...

Conclusion

In summary, converting Ethereum Cashdr (bech32) addresses to legacy Bitcoin Cash addresses requires some additional processing. This article provides a step-by-step guide on how to perform this conversion using Python code. While the format used by different wallets and platforms may vary, understanding these differences is essential for seamless integration with various cryptocurrency systems.

Note: It is always a good idea to double-check the wallet address format before attempting the conversion, as the result may vary depending on your specific implementation.