What private key need use for it?
if I have 2 inputs..
Depends on what you want to achieve. If you want to invalidate that transaction, just use any of the input and create a new transaction.if I have 2 inputs..
If you want to spend both the inputs to a different address, you will have to craft a transaction with both of the inputs in the transaction. You have to use both of the private keys to sign or it won't be valid.
I try use https://coinb.in/#sign
There is one fill for Private key.
I use 2 inputs..
For the second time, the raw transaction has to be signed with the first private key first.
