Guides

LineNews — hidden groups

Hidden groups let LineNews reporters coordinate privately and safely — for example to organize, verify facts together, or protect each other. They are end-to-end encrypted, invite-only, and not tied to your account. This page explains how they work and, just as honestly, their limits. For the broader picture see LineNews.

What hidden groups are#

A hidden group is a private, encrypted conversation that does not appear in any directory or search. There is no way to discover it: you join only with an invite code that an existing member shares with you out of band (in person, or over Signal). Everything inside — messages and even the group's name — is encrypted on the devices of the members; the server only moves sealed data between them.

How to create or join a group#

Open LineNews from the Trends tab, then tap the people icon to reach Hidden groups.
Create: give the group a name (visible only to members) and it is created instantly. The encryption key is generated on your phone.
Invite: from inside the group, create an invite code and share it out of band. The code contains the group's key, so treat it like a secret — send it in person or over Signal, never on a public channel.
Join: paste an invite code into Join with code. You are added and can read messages from that moment on.

How the encryption works#

Each group has a single secret key (NaCl secretbox). That key is created on a member's device and never sent to the server. It travels only inside the invite code, out of band. Every message is encrypted with the group key on your phone before it is uploaded, and decrypted only on the devices of other members. The server receives and stores an opaque block of ciphertext and nothing else — it cannot read a single message.

What the server can never see#

The keys — they exist only on members' devices (in the phone's secure keystore).
The messages or the group name — stored only as ciphertext the server cannot open.
Who you are — membership is a random opaque token, not your account. There is no readable map of who is in a group tied to real identities.
Your IP — the group endpoints are not logged and your address is not passed to the application, exactly like anonymous LineNews posts.

The limits, and how to remove someone#

We are honest about what this does not do. There is no per-message forward secrecy yet (a group uses one key per "epoch"), so anyone who has the current key can read new messages until the key is rotated. The server still sees minimal routing metadata — that some opaque token wrote to some opaque group, and when. To remove a member, rotate the group key: new messages use a new key, and you share the new invite code only with the members who remain. Someone removed keeps only the messages they already received. If you leave a group, its keys and messages are wiped from your device.

Send invite codes in person or over Signal — never on a public or logged channel. The code carries the key.
Use single-use, short-lived invites (the default) and rotate the key if an invite may have leaked.
Remember the content can still identify people: be careful with names, faces and details inside messages and media, just as on the rest of LineNews.
If your life could be at risk, combine hidden groups with Tor/Signal/SecureDrop and a protected network — see LineNews.