public/subjects/blockchain/generate-address

Generate Address

Instructions

Create a function generateAddress() that generates a pair of cryptographic keys using the elliptic curve secp256k1. The return value is an object with members:

• privateKey, a private key as a string (pkcs8/pem format)
• publicKey, the corresponding public key as a string (spki/pem)
• address, an address to identify this account. The address is the hash sha256 of the publicKey (in format spki/der) prepended with '01'

Usage

console.log(generateAddress())

// expected result :
{
  privateKey: '-----BEGIN PRIVATE KEY-----\n' +
    'MIGEAgEAMBAGByqGSM49AgEGBSuBBAAKBG0wawIBAQQg6wEoiAc7tEeOfh1HPVMw\n' +
    'z/eNG/D30JziVWjq8bW35MChRANCAAQP0WsGc3VmBsXO6Iz+LKxPPWNRb2DqUJKY\n' +
    '8Qh7qVvB4rExjUR0DhgUJrTC9tCPy3aiYGbXYLzuXTuOBcPbUiJq\n' +
    '-----END PRIVATE KEY-----\n',
  publicKey: '-----BEGIN PUBLIC KEY-----\n' +
    'MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAED9FrBnN1ZgbFzuiM/iysTz1jUW9g6lCS\n' +
    'mPEIe6lbweKxMY1EdA4YFCa0wvbQj8t2omBm12C87l07jgXD21Iiag==\n' +
    '-----END PUBLIC KEY-----\n',
  address: '01598fbb0e68eaa369d361f7b59157d80a91b2b78de74bc2ff71f6a44b272af368'
}

Relevance

• The secp256k1 curve is used several blockchains to generate keys.
• An user account is identified using an address. The address is computed from the public key using hash functions, splits and concatenations.
  • In Bitcoin hash160 is used in the process and the address starts with '1', '3' or 'bc1'.
  • In Ethereum keccak-256 is used and addresses are appended with 'Ox' that denotes an hexadecimal number.

Notions

• Node.js crypto generateKeyPairSync
• Bitcoin invoice address