Understanding Bitcoin Message Signing Implementation: Python vs. Electrum
Bitcoin’s distributed and open-source ledger is built on a complex cryptographic system based on strong secure coding practices. In this article, we will explore the differences between how Bitcoin message signing results are implemented in Python compared to its native Electrum wallet.
Background: Bitcoin Message Signing
When sending a transaction on the Bitcoin network, miners verify that the sender has sufficient funds to cover the transaction fees and that the transaction is valid. To achieve this, they use the public key associated with each private key in the wallet. This process involves hashing the message (transaction) with the sender’s private key using SHA-256 and then encrypting it with the sender’s public key.
Python implementation: bit
In Python, the Bitcoin cryptographic library (bit) provides a simple and secure way to handle private keys and message signatures. The “Key” object represents the private key in WIF format, while the “verify_sig” function takes a hash and signature as input and attempts to verify them.
bit import key
wif_private_key = 'Kxb19KFrrqrmT79bvG4tnKibVcgppavcvjkP1iBGGjnH787H39QG'
Create a new PrivateKey object from the WIF private keyprivate_key = Key.from_wif(wif_private_key)
Get the sender's public address using the private keypublic_address = private_key.get_public()
Hash the transaction with the private key and get the signaturetransaction_hash = private_key.hash_transaction(public_address, 0.0001)
signature = private_key.sign(transaction_hash)
Verify the signature against the hashresult = verify_sig(private_key, transaction_hash, signature)
result (result)
Implementation in Electrum: ecdsa
In contrast, the Electrum wallet implementation uses the ECDSA (Elliptic Curve Digital Signature Algorithm) algorithm to sign messages. This library provides a more secure and efficient way to handle private keys and signatures.
bit import key
wif_private_key = 'Kxb19KFrrqrmT79bvG4tnKibVcgppavcvjkP1iBGGjnH787H39QG'
Create a new PrivateKey object from the WIF private keyprivate_key = Key.from_wif(wif_private_key)
Get the sender's public address using the private keypublic_address = private_key.get_public()
Hash transaction with private key and get signaturetransaction_hash = private_key.hash_transaction(public_address, 0.0001)
signature = private_key.sign(transaction_hash)
Verify signature against hashresult = verify_sig(private_key, transaction_hash, signature)
result (result)
Differences in Results
When both implementations are run with the same private WIF key and identical transaction data, we can observe some differences:
- The result of the Bit implementation may print a different error message or exception than the Electrum implementation.
- In general, the “Electrum” implementation may produce more cryptic output or warnings related to elliptic curve operations.
- Some differences in the generated code and debug information may appear due to the differences between the Python and ECDSA implementations.
In summary, although both implementations have similar goals, the results of Bitcoin message signing are implemented differently in Python than in its native Electrum wallet. Understanding these differences is essential for the safe and reliable development of cryptocurrencies.
