Signal provides end-to-end encrypted calling and messaging. We cannot decrypt or otherwise access the content of a call or a message.
Certain information (e.g. a recipient’s identifier, an encrypted message body, etc.) is transmitted to us solely for the purpose of placing calls or transmitting messages. Unless otherwise stated below, this information is only kept as long as necessary to place each call or transmit each message, and is not used for any other purpose.
The phone number or identifier you register with.
Randomly generated authentication tokens, keys, push tokens, etc. necessary for setting up a call or transmitting a message.
IP addresses may be kept in memory for rate limiting or to prevent abuse.
Information from the contacts on your device may be cryptographically hashed and transmitted to the server in order to determine which of your contacts are registered.
We do not share your information with companies, organizations, and individuals outside of OWS unless one of the following circumstances applies:
With your consent.
Through normal communication with a federated server operated by another entity. Some Signal users might be registered with other providers (e.g. CyanogenMOD), which requires passing messages, synchronizing views of registered users, etc.
When legally required.
We will share the information we have with entities outside of OWS if we have a good faith belief that access, use, preservation, or disclosure of the information is necessary to: