Secure Chat

How it works

1. Choose a display name and how long the chat should last: 1 hour, 24 hours or 48 hours.
2. Send the private link to the people you want to talk to (up to 20 people can be in a chat). Reading it out over the phone? Make an 8-character short code instead.
3. Chat and send files. New messages appear within a couple of seconds. Anyone who joins can read the conversation from the start.
4. When the time is up, or the person who started the chat ends it, every message and file is permanently deleted from our server. A chat that has been reported is closed to everyone in it, but kept until our team has reviewed the report.

Security, honestly

• End-to-end encrypted. Your browser makes a random key and keeps it in the part of the link after the #, which browsers never send to websites. Messages, names and files are encrypted with AES-256-GCM before they leave your device. We store only scrambled data we have no key for.
• Anyone with the link can read and post. Treat the link like a password. Leave a chat and it's forgotten on this device.
• Display names aren't verified. Anyone can type any name. The number beside each name (#1, #2…) is given out by our server and can't be shared, so two people using the same name will have different numbers.
• Check the fingerprint. Everyone with the same link sees the same four words. If yours differ from the other person's, you're not in the same chat.
• Short codes are a convenience. The code unlocks an encrypted copy of the link's key. When it's typed into this page or opened from the short link, the code itself never reaches us. But an 8-character code is far easier to guess than the full link, so it only works 5 times within 15 minutes. Use the full link when you can.
• We can't scan encrypted files. Your browser refuses programs, scripts, shortcuts, disk images and disguised file names before encrypting, and checks again before saving a download. Files are always saved, never opened. Only open files from people you trust.
• What we can see: that a chat exists, how many people joined, when messages were sent and their sizes, file sizes, and IP addresses of people who create or join it. That's deleted with the chat.

Acceptable use

Don't use Secure Chat for anything illegal, including child sexual abuse material, terrorist content, threats, harassment, fraud or spam. We can't read chats, but we act on reports: we can end any chat, block networks that abuse the service, and we cooperate with UK law enforcement where the law requires it.

To report a chat, press Report inside it. Your report shares the chat's key with our team so we can read it, and the chat is kept as evidence until we've reviewed it, even if it's ended or runs out of time. If someone is in immediate danger, call 999. You can also report child sexual abuse imagery to the Internet Watch Foundation.

Limits

• Up to 20 people in a chat, 5,000 messages and 4,000 characters per message.
• Files up to 100 MB each and 500 MB per chat. You can send 5 files an hour and 1 GB a day.
• 10 new chats a day from one network.
• Links in messages aren't clickable, to protect against phishing. Copy them only if you trust the sender.