Validate your certificate

Compute the SHA-256 hash of each individual file included in the project. There are many utilities for this. On Linux or macOS, run the following command in your terminal:

Terminal command:

You can also use online services such as SHA256 Online Checksum.

SHA-256 is a standard algorithm — it will always produce the same result regardless of the tool used.

Remember to also hash the project cover file. This is a text file containing the project title and description, downloadable from the Bernstein app.

Combine the hashes into a single project fingerprint:

1. Sort all individual hashes alphabetically
2. Concatenate them into a single string
3. Compute the SHA-256 hash of the concatenated string

The result is your project fingerprint. You can verify it against the fingerprint shown in the Bernstein app under your project.

To use the project hash as a Bitcoin key, you need to convert it from HEX format to WIF (Wallet Import Format). We provide a Python script for this conversion.

Start by installing the required Python package:

Save the following Python script as hex2wif.py:

import sys, hashlib, base58

def hex_to_wif(hex_key):
    extended = "80" + hex_key + "01"
    first_sha = hashlib.sha256(bytes.fromhex(extended)).digest()
    second_sha = hashlib.sha256(first_sha).digest()
    checksum = second_sha[:4].hex()
    return base58.b58encode(bytes.fromhex(extended + checksum)).decode()

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python hex2wif.py <your-project-hash-hex>")
        sys.exit(1)
    print(hex_to_wif(sys.argv[1]))

Then run the script with your project hash:

The script will output the corresponding key in WIF format. You can verify the result in the Bernstein app by clicking the key icon next to the blockchain certificate in your project.

In this step, you need to derive the compressed public key from the WIF private key obtained in Step 2. This is a standard Bitcoin cryptographic operation.

You can use this online tool: Bitcoin Key Compression Tool

Paste the WIF key from Step 2 and the tool will display the associated compressed public key. This is the Data Public Key — one of the three keys that make up the certificate address.

Now that you have derived the Data Public Key from your files, combine it with the Owner Public Key and Bernstein Public Key — both found on the certificate PDF — to construct the 3-of-3 MultiSig Bitcoin address.

Save and run the following Ruby script:

require 'digest'
require 'base58'
require 'bech32'

def decode_hex(hex)
  [hex].pack('H*')
end

def sha256(data)
  Digest::SHA256.digest(data)
end

def hash160(data)
  Digest::RipeMD160.digest(sha256(data))
end

def p2sh_multisig(keys)
  script = "\x53" # OP_3
  keys.sort.each { |k| script += [k.length / 2].pack('C') + decode_hex(k) }
  script += "\x53\xae" # OP_3 OP_CHECKMULTISIG
  h = hash160(script)
  version = "\x05"
  payload = version + h
  checksum = sha256(sha256(payload))[0..3]
  Base58.binary_to_base58(payload + checksum, :bitcoin)
end

def p2wsh_multisig(keys)
  script = "\x53"
  keys.sort.each { |k| script += [k.length / 2].pack('C') + decode_hex(k) }
  script += "\x53\xae"
  witness_hash = sha256(script)
  Bech32::SegwitAddr.new(hrp: 'bc', ver: 0,
    bytes: witness_hash.unpack('C*')).addr
end

puts "Select protocol version:"
puts "1 - Protocol 1 (P2SH)"
puts "2 - Protocol 2 (P2WSH SegWit)"
version = gets.chomp.to_i

keys = []
%w[Data Owner Bernstein].each do |name|
  print "Enter #{name} Public Key: "
  keys << gets.chomp
end

address = version == 1 ? p2sh_multisig(keys) : p2wsh_multisig(keys)
puts "\nBitcoin Address: #{address}"

Run the script from your terminal:

Follow the prompts: select your protocol version, then enter the three public keys one by one. The script will output the Bitcoin address.

Protocol 1 (legacy) generates a P2SH address. Protocol 2 (current) generates a SegWit P2WSH address. Check your certificate to determine which protocol version applies.

Finally, look up the Transaction ID from your certificate PDF on any blockchain explorer.

We recommend Blockstream.info orBlockchair.com.

Find the address in the transaction's output list and compare it with the address you computed in Step 4.

Congratulations — you have independently proven the existence and integrity of the information included in your project, without relying on any third party.