Privacy-focused end-to-end encrypted browser-based group chat.

CryptNet.Chat is an anonymous browser group chat where the room secret stays in the `#k=` invite fragment, messages are encrypted client-side before upload, and the server stores ciphertext instead of readable chat history.

Use it for private group messaging, temporary coordination rooms, secure browser chat links, and invite-only conversations where messages auto-delete 48 hours after they are sent.

Server stores Room ids, encrypted messages, session tokens, timestamps, and encrypted attachment payloads.

Message crypto HKDF-SHA-256 key derivation with AES-GCM, plus an authenticated previous-message chain for tamper detection.

New joins New devices only fetch messages sent after they join the encrypted room.

Invite rotation Rotate the room invite to a new epoch before sharing it with a new member.

Retention Messages are deleted automatically 48 hours after they are sent. Rooms stay available until you stop sharing the invite.

Supported Text messages, encrypted image attachments, anonymous aliases, and optional room codes.

Create room

Create a private encrypted group chat, generate a random room key locally, and optionally require a separate room code before new visitors can join.

Open invite

Paste a full invite link to join an existing end-to-end encrypted browser chat. If the room owner set a room code, enter it here or you will be prompted on the room page.

How it works

CryptNet.Chat is a browser-based encrypted group chat. When you create a room, the browser generates a random room secret and keeps it in the invite URL fragment so the server never receives that secret in normal HTTP requests.

Each message is encrypted in the browser before upload. The server stores encrypted message envelopes and delivers ciphertext back to other members who already have the invite secret.

Why use it

No account required for private group messaging.
Useful for temporary encrypted rooms and anonymous group chat links.
Runs in the browser, so participants can join quickly from any modern device.
New joiners do not receive older server history from previous room activity.

Privacy model

The service is privacy-focused and end-to-end encrypted in the sense that message content is encrypted client-side and the server stores ciphertext instead of plaintext. Invite rotation and authenticated message chaining help limit stale-room access and detect tampered history.

The server still sees metadata such as request timing, ciphertext size, and IP-level traffic. This is a shared-secret room model rather than a full identity-based messenger.

Best fit

This works best for private collaboration rooms, ephemeral project threads, secure browser chat for small groups, and invite-only encrypted discussions where a short retention window matters.

If you need a privacy-focused browser group chat without app downloads or user registration, this is the core use case CryptNet.Chat is built for.

FAQ

Is CryptNet.Chat really end-to-end encrypted?

Messages are encrypted in the browser before upload, and the room secret stays in the invite fragment. The server stores encrypted messages, not plaintext chat content. The main trust assumption is the frontend origin that serves the JavaScript.

Can new members read old encrypted group chat messages?

No. Fresh devices only receive messages sent after they join the room. If you rotate the invite before sharing it with a new person, older epochs stay unreadable to them from the server side.

Does the browser-based group chat keep history forever?

No. Encrypted messages are deleted automatically 48 hours after they are sent, so room history rolls forward instead of being stored forever.

Do I need to install anything?

No. CryptNet.Chat is browser-based, so people can create or join an encrypted room directly from the web app with an invite link.