There is probably no amount of protections which are appropriate for using SMS to send commands to a server. It's not only unencrypted the entire trip but SIM-j

There is probably no amount of protections which are appropriate for using SMS to send commands to a server. It's not only unencrypted the entire trip but SIM-jacking and caller ID spoofing are all very well-worn exploit paths. I can email my house, which is at least encrypted in transit, and then I stack an extra couple nonstandard abuses of email headers to validate the source, which all is impossible with SMS.