Communication · 2013
End-to-end encrypted messaging
Messages only the sender and recipient can read, for over a billion people by default.
Open Whisper Systems developed the Signal Protocol in 2013 for TextSecure, with forward secrecy through its Double Ratchet algorithm. WhatsApp adopted it for all users in 2016, bringing strong encryption to more than a billion people at once.
What it built on 2
Related measurements
The dashed line marks when it first worked.
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