Introducing: String Phone

"Nothing is as secure as a string phone" –The NSA

As you can probably tell from previous posts, I’ve been pretty into hardware lately. I’ve especially been building things like home sensors and controllers, so I have a central computer reading motion, temperature, humidity, light and other values in the house and deciding whether the lights or air conditioning need to be on or off.

I also want to be able to turn these on and off from my mobile phone, from anywhere in the world. The problem with that is that I need a way to ensure that only my phone can turn things on in my house. I wouldn’t want someone to be able to turn the heating on in my house at full blast when I’m not there and waste all my electricity bill (or set fire to something).

TLS is a pretty good solution, as it ensures confidentiality between client and server, but it does nothing for verifying the client or securing communications against a malicious server. I needed something better, and I couldn’t find something readily available. So I set out to write it. Thus, string phone was born.

String phone is a

Continue reading…