Signal is a mobile communication app which employs end-to-end encryption, making it very difficult for anyone other than the sender and receiver to access messages and phone/video calls.
Because of its secure data deletion protocols, the app is not suitable for government business, as it does not allow for the preservation of public records.
For the average person, however, Signal is a highly effective way of ensuring privacy and freedom of expression.
Messages on platforms such as WhatsApp and iMessage are only end-to-end encrypted in certain situations, while Signal makes this a default position, increasing user security.
Provided all participants’ phones have not been hacked, messages cannot be accessed outside of the sender and receiver.
The source code for Signal is available online and is frequently audited by experts in the field.