Briar is a messaging app for activists and journalists that prioritizes privacy and security. Messages are synced directly between users’ devices, even without internet access using Bluetooth or Wi-Fi. The app can also sync through the Tor network for added protection against surveillance. Briar prevents metadata surveillance by encrypting contact lists, content surveillance by encrypting communication end-to-end, and content filtering with its decentralized design. It also protects against takedown orders and denial of service attacks. Briar’s long-term goal includes supporting secure, distributed applications for crisis mapping and collaborative document editing to aid social movements worldwide.
https://briarproject.org/how-it-works/