Bitcoin Tutorials - Herong's Tutorial Examples - v1.06, by Herong Yang
Verify Merkle Root of 7 Transactions
This section describes how to verify the Merkle Root of 7 transactions in a Bitcoin block.
Now let's try a block with more transactions.
Get the block # 500 from Bitcoin Test Network:
C:\>\local\bitcoin-0.15.1\bin\bitcoin-cli -testnet getblockhash 500 00000000a2424460c992803ed44cfe0c0333e91af04fde9a6a97b468bf1b5f70 C:\>\local\bitcoin-0.15.1\bin\bitcoin-cli -testnet getblock 00000000a2424460c992803ed44cfe0c0333e91af04fde9a6a97b468bf1b5f70 ... "height": 500, "merkleroot": "dd3f288510dd3b632940bd3fb1db162d3ff99b19ddb0c586cfa3ac9a76d42517", "tx": [ "a647d0c4112b4727f3c856782ff6bbaf099be929b27214a8e0dfedee4383eb68", "24b8a4c788b8c805b810438ddd99e569e184ff20f4394ac49a6d832e69f57242", "c5ffd70c3bc4998465cef55ed6d5d831ab3a550406423eb611117ed8ee41c278", "4692772a73ea834c836915089acf97f2c790380a2b8fd32f82729da72545d8c5", "82d6d88081e3e0eb36730f7f3aedb17228142b9e00a6dbaab4b53b798d0742c1", "fc407d7a3b819daa5cf1ecc2c2a4b103c3782104d1425d170993bd534779a0da", "95ad3ffb2a9426d6f5f5b97a134d90153ae16c9375f74eb385f481cff2771d77" ], ...
Here is my Python script and test result:
C:\>type Merkle-Root-Hash-of-Test-500.py #- Merkle-Root-Hash-of-Test-500.py #- Copyright (c) 2018, HerongYang.com, All Rights Reserved. import hashlib import binascii def doubleSha256(hex): bin = binascii.unhexlify(hex) hash = hashlib.sha256(bin).digest() hash2 = hashlib.sha256(hash).digest() return binascii.hexlify(hash2) # Getting transaction hashes from blockexplorer h1 = "a647d0c4112b4727f3c856782ff6bbaf099be929b27214a8e0dfedee4383eb68" h2 = "24b8a4c788b8c805b810438ddd99e569e184ff20f4394ac49a6d832e69f57242" h3 = "c5ffd70c3bc4998465cef55ed6d5d831ab3a550406423eb611117ed8ee41c278" h4 = "4692772a73ea834c836915089acf97f2c790380a2b8fd32f82729da72545d8c5" h5 = "82d6d88081e3e0eb36730f7f3aedb17228142b9e00a6dbaab4b53b798d0742c1" h6 = "fc407d7a3b819daa5cf1ecc2c2a4b103c3782104d1425d170993bd534779a0da" h7 = "95ad3ffb2a9426d6f5f5b97a134d90153ae16c9375f74eb385f481cff2771d77" # Converting them in little-endian hex notation h1 = binascii.hexlify(binascii.unhexlify(h1)[::-1]) h2 = binascii.hexlify(binascii.unhexlify(h2)[::-1]) h3 = binascii.hexlify(binascii.unhexlify(h3)[::-1]) h4 = binascii.hexlify(binascii.unhexlify(h4)[::-1]) h5 = binascii.hexlify(binascii.unhexlify(h5)[::-1]) h6 = binascii.hexlify(binascii.unhexlify(h6)[::-1]) h7 = binascii.hexlify(binascii.unhexlify(h7)[::-1]) # Rount #1 h1 = doubleSha256(h1+h2) h2 = doubleSha256(h3+h4) h3 = doubleSha256(h5+h6) h4 = doubleSha256(h7+h7) # Rount #2 h1 = doubleSha256(h1+h2) h2 = doubleSha256(h3+h4) # Rount #3 hash = doubleSha256(h1+h2) # Converting result to big-endian hex notation root = binascii.hexlify(binascii.unhexlify(hash)[::-1]) root = str(root,"ascii") # Comparing with Merkle Root on Bitcoin Core exp = "dd3f288510dd3b632940bd3fb1db162d3ff99b19ddb0c586cfa3ac9a76d42517"; print("Match the Bitcoin network: "+str(root==exp)) print("Merkle Root:\n "+root) C:\>Python Merkle-Root-Hash-of-testnet-500.py Match the Bitcoin network: True Merkle Root: dd3f288510dd3b632940bd3fb1db162d3ff99b19ddb0c586cfa3ac9a76d42517
Cool. You should be able to make a generic script to verify the Merkle Root of any Bitcoin block now.
Table of Contents
Data Components of Bitcoin Block
Data Properties of Bitcoin Block
Calculate Double-SHA256 Hash with Python
Verify Merkle Root of 2 Transactions
►Verify Merkle Root of 7 Transactions
Data Structure of Bitcoin Block
"getblock blockhash 0" - Serialized Hex Block Data
Block Hash Calculation Algorithm
Block Hash Calculation in Python
Calculate Double-SHA256 Hash with Java