Verify that a phone is using the most secure cell protocols.
Privacy Cell is a small app that displays the cell phone protocol information. It is released under the GPLv3+ license. The source code is available from gitweb.stoutner.com.
Privacy Cell is available on F-Droid, Google Play, the Amazon AppStore, and the Galaxy App Store.
At the time of this writing, many cell phone networks are switching from 4G (4th Generation) to 5G networks. The 5G network protocols were specifically designed to protect against some of the known insecurities of the older protocols, including those that allowed stingrays (IMSI catchers) to perform man-in-the-middle attacks on cell phone networks. To ease deployment and backwards compatibility, 4G and 5G networks can run together in what is known as 5G NR (New Radio) NSA (Non-Standalone) mode. This uses the 4G network for the control channel and the 5G network for the data communication. However, 5G NR NSA does not provide protection against stingrays. Android has access to all the information it needs to know if it is connected to a 5G NR NSA or a 5G NR SA (Standalone) network, but it doesn’t display that information to the user. The purpose of Privacy Cell is to make that information easy to access.
Privacy Cell can also warn you when you are connected to antiquated 2G and 3G networks.
In answer to a number of questions I have received, it is important to note that Privacy Cell cannot improve the security of your cell phone connection. Only your cell phone provider can do that, by installing newer hardware on their cell phone towers. Also, Privacy Cell cannot tell you if your cellular communications are being intercepted. It can only tell you if you are connected to secure or insecure protocols, but it cannot tell you if someone is intercepting information sent over an insecure protocol. If the day ever comes when all legitimate cell phone connections use secure protocols, then you can assume if you are ever connected to an insecure protocol it indicates an active attack. But for now, because so many cell phone companies use outdated equipment, connecting to older protocols doesn’t necessarily indicate that anything bad is happening.
The Git repository can be cloned by running the following command:
git clone https://git.stoutner.com/PrivacyCell.git
Feature requests and bug reports can be submitted at redmine.stoutner.com. There is also a forum to handle technical support.
Privacy Cell development can be followed at https://fosstodon.org/