Signal (Messenger)
More info
- Creator
- Moxie Marlinspike
- Released
- Owner
- Signal Foundation
- Type
- Messaging app
- License
- GPL-3.0 / AGPL-3.0
- Website
- signal.org
- Source
- github.com/signalapp
- Wikipedia
- en.wikipedia.org
End-to-end encrypted chat app from the non-profit Signal Foundation — the gold standard for secure communication, funded by donations (incl. USD 50 million from Brian Acton, WhatsApp's co-founder).
Built on the Signal Protocol (Double Ratchet + X3DH + Sesame), open-source clients and server. No metadata trail: contact discovery via sealed sender, group size encrypted, "sealed sender". Phone number as primary identifier — controversially — now supplemented with usernames.
Used by journalists, dissidents, EU commissioners and the tech industry's security crowd. The Signal Protocol is also used by WhatsApp, Facebook Messenger, Google Messages (RCS) and Skype.