Thank you Tom. Great Article. But I have one question. I know the private key in your article is a hexadecimal format, but usually people use WIF format starting from L or K as a bitcoin private key such as “L5kTgbdZeV9iz7U6FsvN5nADsFiG823upDbBGfiAtQZYVWwkcsjW”. How do I make a signature with WIF private key? I never figure out how to convert from WIF to hex format private key. It would be really appreciate if you can share that too. Thank you.