When it comes to messaging securely, Signal is the best available. It's end-to-end encryption protocol is highly-regarded in the security industry. Plus it's design and feature set make it easy to send text messages and make calls with individuals or groups. Why not use the best?
End-to-end encryption is crucial when messaging securely. The goal is to make it virtually impossible for anyone but the sender and recipient to view the contents of a message.
Signal is available for iOS and Android and requires a phone number to get started. Signal taps into your address book, and you can then begin sending encrypted text messages and media, or call over Wi-Fi or cellular network.
When it comes to group messaging, Open Whisper claims "the Signal server never has access to any group metadata such as the membership list, group title, or group icon."
Signal is open source and that means anyone can audit the code to theoretically verify the security of the service. "Signal is the only private messenger that uses open source peer-reviewed cryptographic protocols to keep your messages safe," claims Whisper Systems.
Five security researchers in October 2016 published research that found no major flaws in the Signal protocol.
Signal allows users to verify who they are messaging. As The Intercept explains, each voice call is verified by displaying two words on the callers' phone screens. Callers can then repeat the two words to each other to verify who is on the other end. For texting, each user gets their own identity key.
Ex-NSA whistleblower and cyber security figure Edward Snowden tweeted in an apparent taunt to the FBI that he uses Signal every day.
Use on the big screen is limited. Signal has has been available for Chrome since mid-2016 and functions similar to the mobile versions. Signal is not compatible with tablets, but the group says support for larger screens is in the roadmap.