Anything related to HTTPS.
HTTPS is the secure tunnel between a browser and a server, that prevents people from snooping on your internet traffic. Like, since I'm using https://tilde.camp/wiki no one will know which article I'm editing right now ;D
Learn how HTTPS works together with Tor-Browser for better security:
https://www.eff.org/pages/tor-and-https
Stay secure with HTTPS-Everywhere:
https://www.eff.org/https-everywhere
P.S. Aaron Swartz did a lot of work to create HTTPS-Everywhere. What a G! That kid got a lot done in his short life! R.I.P.made