nsh: A More Secure and Convenient Remote Shell than SSH

The security of ssh relies on the assumption that user knows the public key of remote machine. This is because there is no intrinsic relationship between the IP address and public key. NKN client enables free end to end data transmission in a purely decentralized way. The only requirement is that the remote machine has Internet access (can establish outbound http and websocket connections). Any software, as long as it has Nkn client, can run command using nkn-shell-daemon. It uses nkn to listen for messages that are encrypted and sent from a list of authorized addresses or public keys. Then it parses the messages as shell commands, executes them, and sends back results from stdout or stderr.