Creating a Bech32 Address from an ECDSA Public Key

Following the transition from Bitcoin Cash (BCH) to Ethereum Classic (ETC), many users are wondering how to convert their existing Bitcoin Cash addresses to Ethereum Classic addresses using Bech32. In this article, we will explain the process step by step and provide code examples in ECDSA and ECDH.

ECDSA Public Key

Before we dive into the conversion process, let’s briefly look at how to create an ECDSA public key:

• Create a new private key using the ecdsa_generate_keypair command:

$ openssl ecparam -genkey -out my_private_key.pem 4096

This will generate a 4096-bit private key.

• Use the private key to create a public key using the ec pública_key command:

$ openssl ecparam -in my_private_key.pem -pubout -out my_public_key.pem

This will generate the corresponding public key in PEM format.

Creating a Bech32 address from an ECDSA public key

Now that we have our ECDSA public key, let’s create a Bech32 address using the ecrecover command and then bech32-encode.

Here are the steps:

• Create a new private key using the ecdsa_generate_keypair command (same as above):

$ openssl ecparam -genkey -out my_private_key.pem 4096

• Use the private key to recover the original public key:

$ openssl ecrecover -private my_private_key.pem -pubkey my_public_key.pem -inkey my_private_key.pem

This will generate a new public key in PEM format.

• Convert the new public key to Bech32 format using the bech32-encode command (same as above):

$ bech32-encode -type bech32 -o my_address.bech32 my_public_key.pem

This will generate a new file named my_address.bech32, which is the Ethereum Classic address corresponding to your ECDSA public key.

Code Examples

Here are some code examples in ECDSA and ECDH:

ECDSA Code

import ecc









Create a new private key using the ecdsa_generate_keypair command (same as above)
private_key = ecc.ECKey.generate(4096)

Use the private key to retrieve the original public key
public_key = ecc.ECPublicKey.from_private_key(private_key, 'my_private_key.pem')

Convert the public key to Bech32 format using the bech32-encode command (same as above)
bech32_address = bech32.encode('type=bech32', 'o') + public_key.public_bytes(
encoding=ecc.Encoding.PEM,
format='spki'
)
print(bech32_address) 
Output: my_address.bech32

ECDH Code

“javascript

const bech32Address =type=bech32, o=${publicKey.publicBytes().toBuffer()}`;

console.log(bech32Address);

” “

Note that these code examples assume you have a working OpenSSL installation and are familiar with the commands. Also keep in mind that Bech32 addresses may not always match standard Bitcoin Cash addresses due to the differences between ECDSA and ECDH.