I am trying to create an offline wallet which is hopefully cold. Besides storing the coins, I want it to also sign transaction by transferring the needed data away via a USB. My understanding can be wrong as I am totally new to this, but I think the flow is as below:
- A transaction is created on a PC running fully-synced node, to send an amount from a cold wallet to another wallet
- The data of the transaction is transferred to the cold wallet store on an internet-isolated PC, e.g. a RPi4, via a USB drive
- Data corresponding to a signature for the needed transaction is generated on the RPi4, and the signature data is extracted via the USB thumb drive
- The signature data downloaded to the fully-synced node PC, and is used to complete the transaction and sent to the blockchain
If I want to perform the above, is there any reference I can look at?