I like security, and one of the biggest security holes in my technology concerns text messaging and phone calls. While I can secure my data (for the most part), it is hard to secure traffic over the telephone network, especially with the proliferation of devices like the Stingray.
Awhile ago my friend Jeff introduced me to Red Phone by Open Whisper Systems, which was an app that would encrypt your phone calls. I could never get it to work very well, so I didn’t use it, plus Jeff was the only person I talked with who used it.
Flash forward more than a year, and I’m finding that I quite often don’t get texts from Jeff, while he gets mine just fine. He did some investigation and traced the issue to TextSecure, which was an encrypted text app also from Open Whisper Systems. Apparently I was registered on his phone as a TextSecure user, so it was trying to send text to me by that method. Since I no longer had Red Phone on my device (I play a lot with the software on my mobile devices and had not restored it after a clean install) I wasn’t getting the messages.
I went to install TextSecure and found that it has been replaced by Signal. My, what a difference a year makes. Not only was it easy to use, the app itself is pretty nice. It combines both TextSecure and Red Phone features, and is now the default SMS application on my handy.
Signal is 100% open source. The only way for true security is if everyone has the opportunity to examine the code and look for vulnerabilities. Plus, think about it, if you care about security chances are you want to send sensitive information using the service. Without open source you can’t be sure that information isn’t being intercepted by third parties.
This has resulted in some pretty high endorsements:
Signal is available for both Android and iOS, Note that is uses a data connection to send encrypted SMS messages, so it will count against your data cap. I haven’t had the chance to try out the phone functionality as of yet, but it works fine as a normal SMS client as well.
It is nice to come across such a useful piece of software that is 100% open source, and if I happen to send you SMS messages, be on notice that I will be sending you an invite to Signal (grin).
UPDATE: This is so cool. Since the app uses data instead of the SMS protocol for encrypted texts, it works as long as the mobile device has data. Which means that I can get texts no matter what SIM card is currently in my handy. Cool! So I’m in Germany using my Ortel SIM and I’m able to get SMS messages from friends in the US who have no idea where I am or what network I’m using. Killer feature.