Passwords & encryption
Personal chats, private groups and their files are end-to-end encrypted, so each message can be read only on the devices of the people in them. A room with a password encrypts its messages on your device, using that password.
What's encrypted
| Chat | End-to-end encrypted? |
|---|---|
| Personal chats | Yes, with their files |
| Private groups | Yes, with their files |
| Anonymous rooms with a password | Yes, encrypted with the room password |
| Open anonymous rooms | No. Anyone with the link can read them |
| Communities and their channels | No |
| Status updates | No. AChat's servers can read them; access rules limit who else sees each one |
AChat stores end-to-end encrypted messages in a form its servers and administrators can't read. AChat doesn't keep a copy of your message keys.
Room passwords
- Everyone needs the password to join and read the room.
- Send the password separately from the link.
- Too many wrong tries in a row make you wait some minutes before you can try again.
- New passwords show a strength meter. It's checked on your device, and the password isn't sent anywhere to check it.
Groups and changing members
When a group's members change, the group gets new security keys, so people who left can't read new messages. People who join see messages sent after they join; earlier messages aren't shared automatically.
Checking a linked device
On Account, then Devices, you can compare security codes between two of your devices. If they don't match, remove the device you don't trust. See Devices & recovery key.
The limits
- Anyone in a chat can copy, save or screenshot a message. Encryption protects messages on the way and on the server, not after someone has read them.
- Search looks only at messages already on your device.
- Push notifications never include the message text.
- Losing your recovery key and every linked device means your history can't be restored, by you or by the AChat team.
The full model is in Security & encryption.