Stone to Silicon

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.

See it in the living treeWikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 2

Related measurements

The dashed line marks when it first worked.

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