I’m recently digging into the cryptocurrency Ripple (XRP). However, I found XRP leaks cryptographic explanation for how to sign a transaction.
I could get the cryptographic explanation of address encoding and the public&private key in xrpl.org. But for how to sign a transaction with private key in XRP, I’ve searched online for days but found no such reference. They are just telling me to call API to sign, and I feel hard to understand the API source code.
I want to sign an offline transaction manually, but I got stuck at what to sign. What should be signed with the private key and attached to the transaction? Is there any reference?