code: function createPublicKeyHash (ecdhPublicKey) {
    return crypto.createHash(module.exports.SHA256)
      .update(ecdhPublicKey)
      .digest()
      .slice(0, 16);
  }
docs: Creates a 16 byte hash of a public key.
  
  We choose 16 bytes as large enough to prevent accidentally collisions but
  small enough not to eat up excess space in a beacon.
  
  @param {Buffer} ecdhPublicKey The buffer representing the ECDH's public key.
  @returns {Buffer}