Say it now.
It seals itself later.
Turn a message into a short sealed text and send it through any chat app. Until the time you set, anyone holding it can open it. When time is up, nobody in the world can, not even us.
At least 8 characters, not only digits.
Send the sealed text to the other person. With the Cachet keyboard they just copy it; without it they can paste it here, or tap the link. The link keeps the message after the #, which browsers never send to any server.
This is a read-once message: after it opens once, nobody can open it again.
How it works
Every message has its own random key. The sealed text only carries the key’s number; the key itself lives on our server, and a message with an access password also needs the password to complete it. When the key expires it is wiped, and the sealed text becomes noise that can’t be turned back.
Encrypted on your device
The keyboard or your browser asks the server for a random key and encrypts the message locally. Your text never leaves your device.
Send it anywhere
It’s just text: any chat app, SMS, email or forum will carry it. It can look like a line of Chinese characters, letters, or a single emoji.
Readable until it expires
Whoever has it copies it (keyboard) or pastes it here, opens it on their own device, and sees how long is left and how many times it was opened.
Gone for good
The server’s key is wiped when it expires. Without it, nobody, us included, can ever open the message again.
Why you can trust Cachet
We try to turn “trust us” into “check for yourself”. The details are on Security.
We can’t see your messages
Encryption and decryption happen on your device. The server keeps only random keys, expiry times and read counts.
Open protocol
The protocol, its test vectors and the code this site runs are public and unminified, so anyone can check what we say.
No account
No phone number, no email, no tracking, no analytics. This site loads nothing from third parties.
Wiped on time
Keys are deleted when they expire. A read-once message’s key is deleted the moment it is first opened.
Cachet keyboard · iPhone and Android
Type and seal right inside any chat app. Copy a sealed message and the keyboard shows it with its countdown at once. Chinese pinyin and English built in.