I have installed geth on an offline-computer and created a account with
./geth account new. Than I have copied (USB-Stick) the resulting file from the offline-computers
keystore/ to an online-computer, where I can check the balance of that account. Of course I will never type the passphrase for that account on the online-computer.
How can I transfer Ethers from the account using only geth? (I do not want to install any third-party software on the offline-computer.)
I have read other posts saying "using the unofficial RPC method eth.signTransaction". Unfortunately it's not clear to me, if this is related to geth or an other tool. I would very much appreciate to sign offline just with geth.