In a network of IoT devices like internet-connected Raspberry Pis which sends transactions to the Ethereum blockchain, the Pis need to be able to access their own Ethereum private keys in order to submit the transaction and pay the transaction gas.
Considering that these devices may be deployed out in the field, how do you avoid losing ETH when someone accesses the device and retrieves the private key?
Even if the private key is password protected, this password will need to be stored in plaintext for a program to sign an Ethereum transaction, so if the attacker reads through the code he will be able to find the password protecting the private key.
Is there a better way that storing the private key on these devices deployed in in the field?
