Custom Python Bech32 Auditor
Custom Python Bech32 Auditor
In this final guide, we will build a Python script that performs the 8-to-5 Bit Conversion required for Bech32. This script will take a hexadecimal hash and convert it into the Base32 characters used in modern Bitcoin addresses.
The Bech32 Bit Auditor
# The Bech32 Base32 Alphabet
CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
def convert_8_to_5(data_bytes):
"""Converts 8-bit bytes into 5-bit chunks."""
acc = 0
bits = 0
res = []
for value in data_bytes:
acc = (acc \u003c\u003c 8) | value
bits += 8
while bits \u003e= 5:
bits -= 5
res.append((acc \u003e\u003e bits) \u0026 31)
# Handle remaining bits (padding)
if bits \u003e 0:
res.append((acc \u003c\u003c (5 - bits)) \u0026 31)
return res
def audit_bech32_encoding(hex_hash):
print(f"--- Bech32 Encoding Audit ---")
print(f"[*] Input Hex: {hex_hash}")
# 1. Convert hex to bytes
raw_bytes = bytes.fromhex(hex_hash)
# 2. Perform 8-to-5 conversion
five_bit_chunks = convert_8_to_5(raw_bytes)
print(f"[*] 5-bit Groups: {len(five_bit_chunks)}")
# 3. Map to characters
encoded = "".join([CHARSET[c] for c in five_bit_chunks])
print(f"[SUCCESS] Encoded Data: {encoded}")
# Note: A real address would prepend 'bc1q' and append a 6-char checksum
print(f"[*] Simulated Address: bc1q{encoded}xxxxxx")
# --- Simulation ---
# A standard 20-byte Public Key Hash
test_hash = "79be667ef9dcbbac55a06295ce870b07029bfc01"
audit_bech32_encoding(test_hash)
How to Run the Auditor
-
Ensure you have Python 3 installed.
-
Copy the code into a file named
bech32_auditor.py. -
Run it using
python3 bech32_auditor.py.
Technical Takeaways
-
Alignment: Notice how a 20-byte hash (160 bits) results in exactly 32 Base32 characters ($160 / 5 = 32$). This perfect alignment is one reason why Bech32 was chosen.
-
Bitwise Performance: Unlike Base58, which requires heavy division, this script only uses shifts (
\u003c\u003c) and masks (\u0026). It is extremely fast. -
Missing Checksum: In a real Bitcoin wallet, the
xxxxxxat the end would be a BCH Checksum derived from the HRP and the data to ensure validity.
Congratulations! You have completed the Bech32 Encoding (The SegWit Standard) module. You now understand the bit-level transformation that powers modern Bitcoin commerce.
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