Tag Archives: Bitcoin

Create bitcoin address

Bitcoin and BlockChain are too popular to ignored by technical people.  Hence I also spend some hours to read some books, and do some coding. This blog explains basic steps to create bitcoin address.

Step 1: Generate private key (256 bit, 64 bytes)

import binascii as ba

import ecdsa

import hashlib

import random

def create_priv_key():

   digits = ['%x' % random.randrange(16) for _ in range(64)]

   return''.join(digits)
priv_key = create_priv_key()

print('1. Private key:%s' % priv_key)

Step 2: Generate public key

def build_pub_key(priv_key):

   buff = bytes.fromhex(priv_key)

   sk = ecdsa.SigningKey.from_string(buff,

   curve=ecdsa.SECP256k1)

   pub_key = b'\x04' + sk.verifying_key.to_string()

   return ba.b2a_hex(pub_key).decode()
pub_key = build_pub_key(priv_key)

print('2. Public key:%s' % pub_key)

Step 3: Calculate sha-256

def sha256(key):

    sha = hashlib.sha256(bytes.fromhex(key))

    return ba.hexlify(sha.digest()).decode()
r_3 = sha256(pub_key)

print('3. Public key sha-256:%s' % r_3)

Step 4: Calculate ripedm160

def ripemd160(key):

    rm = hashlib.new('ripemd160')

    rm.update(bytes.fromhex(key))

    return ba.hexlify(rm.digest()).decode()
r_4 = ripemd160(r_3)

print('4. Calculate Step 3 ripemd-160:%s' % r_4)

Step 5: Prefix address with protocol version

r_5 = '00' + r_4

print('5. Prefix Bitcoin protocol version :%s' % r_5)

Step 6: Calculate sha-256 twice

r_6 = sha256(sha256(r_5))

print('6. Calculate Step 5 with sha-256 twice:%s' % r_6)

Step 7: Validation

r_7 = r_5 + r_6[:8]

print('7. Append output last step into Step 5 for validation:%s' % r_7)

Step 8: Encode with base58

addr = base58.b58encode(bytes.fromhex(r_7))
print(‘8. Wallet address: %s’ % addr)