With Briar (thorny thicket, thorny bush), users can exchange information anonymously and, if necessary, without an Internet connection. Communication takes place via the Tor network and does not require a central server. Briar can also establish direct connections to other instances in the immediate vicinity via Bluetooth or WLAN. All conversation content is encrypted and stored only on the devices of the communication partners involved.
New communication partners can only make themselves known to each other directly (device-to-device) and must therefore be in the same place at the same time. An already known contact can be suggested to another known contact via invitation suggestion, which is very restrictive, but also very secure. Briar differs from other messengers in that no personal data such as SIM card, phone number, email address, or messenger ID is required for contact registration. Important user groups for Briar include activists and journalists who rely on secure communication. The technology used (no mandatory internet access) can also be used and helpful in disaster situations.
Briar protects against:
Does Briar offer complete anonymity? No (external; English)
Briar does not hide your identity from your contacts. It provides unlinkability, but not anonymity. This means that no one else can find out who your contacts are, but your contacts might find out who you are.
Briar uses Tor’s hidden service protocol. Participants’ apps do not communicate directly with each other, but first connect to the Tor service running on the device. This is to ensure that communication is completely anonymous and no one can find out who is communicating with whom.
Briar can be downloaded from the official F-Droid store, from the Google Play store - but also directly from the developer page (external).
At the first start a name and a password must be entered. The username can not be changed after that - unless you “forgot” the credentials and create a new, empty database (with a new name). The password is checked for encryption strength. That means, it must be a combination of length and different characters, which is not considered “insecure”. -> MORE INFO??
Adding contacts is only possible if both devices are physically in the same location or by recommending an already existing Briar contact to another (more on this later).
1. direct announcement
The barcode (displayed QR code) of the other device must be read (captured and recognized by the camera) on both devices. Only when this has worked mutually, the contact data is exchanged automatically. Afterwards one is connected and can start texting.
2. announcement by recommendation
If someone has two contacts in Briar and they should be “referred “ to each other, this is possible and has the advantage for them not to have to be at the same place. To do this, you suggest one contact to another as a “contact recommendation” and act as an intermediary:
For the second contact, the procedure is the same as for the first contact.
Due to the operation without a server, Briar needs significantly more power on a terminal than for example a Jabber client. In practical comparisons it has been shown that the power consumption is about 4 times higher. Continuous, daily use is not/hardly possible with a device battery with lower power.
However, ecologically and economically, Briar operation is better overall (compared to decentralized or centralized systems) because only end devices are operated and no servers are required. These require significantly more power for operation and often only a fraction of the continuously provided power is actually used - thus wasting resources.
Start page of the project: https://briarproject.org/ (external)
Briar manual: https://briarproject.org/manual/ (external)
FAQ: https://code.briarproject.org/briar/briar/-/wikis/FAQ (external)
Current release notes: https://code.briarproject.org/briar/briar/wikis/changelog (external)
Minimum Android version: 4.01 (Sdk version 15)
Source code: https://code.briarproject.org/briar/briar (external)