I think it is possible to generate keys on an offline computer and sign. To create a transaction I need to input transactions detail, and somehow I have to transfer signed transaction from offline computer to a online computer to relay the transaction.
Is it possible to do this without using USB storage? I can use a keyboard, or barcode reader to transfer the input transaction hash to an offline computer and the signed transaction back to the online computer. So that private key stays with the offline computer.
What are step-by-step instructions to do this, with any required error check / correction?