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Privacy is not an optional setting in Signal. It is built into every message, every call, and every feature by default. Signal uses advanced privacy-preserving technology that runs constantly in the background, without any configuration required from you.

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End-to-End Encryption

Signal always encrypts your communications from end to end. This means only you and the person you are communicating with can read your messages or hear your calls. No third party, not even the Signal servers, can access the contents of your conversations.
End-to-end encryption is permanently enabled in Signal. You cannot turn it off, and you never need to turn it on manually. Every conversation is protected as soon as it starts.

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The Signal Protocol

The Signal Protocol is the cryptographic engine that powers all Signal communications. It is widely regarded as one of the most secure messaging protocols in the world. The protocol was independently audited and is used not just by Signal, but by other major messaging platforms that have adopted it for their own encryption layers. Key properties of the Signal Protocol:
  • Forward secrecy: Even if a future key is compromised, past messages remain secure.
  • Future secrecy: Continuously rotates keys so future messages are protected even if an old key is exposed.
  • No key escrow: Signal does not hold any decryption keys on your behalf.

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No Ads and No Trackers

Signal is a non-profit organization. The app contains no advertising, no affiliate links, and no behavioral tracking. Your conversations and metadata are never mined for profit or sold to third parties. Your data is yours alone.

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Open Source

Signal’s source code is fully open and available for inspection. The Android client is published under the GNU AGPLv3 license, which means anyone can review the code, audit the cryptographic implementation, and verify that the app does what it claims.
This distribution includes cryptographic software. Before using any encryption software, verify that your local laws permit the import, possession, and use of encryption tools. The U.S. Government Department of Commerce, Bureau of Industry and Security (BIS), has classified this software as Export Commodity Control Number (ECCN) 5D002.C.1.

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Next Steps

Messaging

Explore how to send text, media, and group messages.

Calls

Learn about HD voice and video calling.