Create master public key after HMAC-SHA512
m*G
  
  bc &lt;&lt;&lt;
  “73111678085084231450767103284505018606851115862905010375565411946552667932016
  * 41313771436092106966070828753784402438291933698697412643075684398900444625545”


Careful, G is a secp256k1 elliptic curve generator point. You cannot multiply it as you would a scalar. You need a secp256k1 library to perform scalar x EC-Point operations.