It seems only 2G connection is crackable. Are we safe as long as the device is on 3G/4G network? We should just disable cellular radio when you see the device is on 2G suspiciously in the middle of city(around demonstrations, I suppose)
I'm just going to quote the GitHub README here: "Although A5/3 withstands passive eavesdropping, it can be bypassed by deploying an IMSI-Catcher which can force a mobile device into 2G mode and downgrade then the encryption to A5/1 or disable it."
Here is the best hint I can give you: LEAVE YOUR PHOEN AT HOME when you really have to participate in demonstrations! The main reason why the use of IMSI-Catchers, Stingrays and alike is such a popular tactic for law enforcement agencies is because people are not SMART ENOUGH to think ahaed and leave their phones at home!
No solution for you? Well then, at the very least make yourself your own signal blocking pouch to fully block all Silent SMS: www.killyourphone.com
