Security
and encryption
Transparent information about how we protect your messages and files. Your trust is our priority.
Two-tier protection
Your data is protected by a combination of advanced encryption methods
End-to-end encrypted messages
The text, subject and file names are encrypted with AES-256-GCM right in your browser. When you choose a password, only it protects the key, and neither we nor anyone else has it.
End-to-end encrypted files
Files are encrypted in your browser with the Web Crypto API before upload. With a password, only a recipient who has both the link and the password can open them; without one, the link is enough.
Automatic deletion
Messages and files are automatically deleted after the specified time from delivery. You can choose from 1 hour to 1 year.
Text messages
How your messages are encrypted
AES-256-GCM in your browser
We encrypt the message with AES-256 in GCM mode, which also verifies that nobody has altered the content.
Key protected by a password, or by the link
We wrap the capsule's random key with the password you choose (PBKDF2-SHA256, 600,000 iterations); neither the password nor the key ever leaves your device. Without a password, we wrap the key with a random secret that is part of the recipient's link. We store that secret encrypted so we can send the link on the delivery day.
The server only sees encrypted data
We store only encrypted content. To deliver, we see the recipient's email and phone (if given), the sender's name and email (when sent without an account), the delivery time and file sizes and types.
Decrypted by the recipient
The recipient opens the link from the email, enters the password if there is one, and the message is decrypted only in their browser.
What we know about your message
We cannot read the message, the subject or the attachments of a password-locked capsule; if the password is lost, nobody can open it, not even us. A capsule without a password opens for anyone with the link; we keep the secret from the link encrypted and use it only to send the link. To deliver, we see the recipient's email and phone (if given), the sender's name and email (when sent without an account), the delivery time and file sizes and types. Messages sent before 14 October 2026 used an older mode in which text was encrypted on the server.
Files
True end-to-end encryption of your files
Browser encryption
Files are encrypted directly in your browser using Web Crypto API before upload to the server
Zero-knowledge for files
The server only sees encrypted data. We cannot see your file content, even if we wanted to
Key protected by a password, or by the link
The file key is wrapped with your password, so the link from the email alone is not enough. If you send the capsule without a password, the link unlocks it on its own.
Integrity verification
Each encrypted chunk has a hash for verification that data hasn't been modified or corrupted
True E2EE
Files are encrypted end to end and the server stores only encrypted data. With a password, only the recipient with the link and the password can decrypt them; without one, anyone with the link can.
Data lifecycle
What happens to your data from creation to deletion
Creation and encryption
The message and files are encrypted in your browser. We store only encrypted data in the database and blob storage.
Scheduled delivery
The message waits encrypted in the database until the scheduled time. Every minute it's checked if it's time to deliver.
Delivery and viewing
At the scheduled time, the recipient gets an email with a link. The message is decrypted and shown in their browser, after they enter the password if the sender chose one.
Automatic deletion
After the specified time from delivery, the message is automatically deleted. The recipient sees a 410 Gone error.
Physical removal
MongoDB TTL index automatically deletes the document from the database. A cron job deletes old files from blob storage every hour.
Complete erasure
The data is deleted from the database and from file storage. It disappears from database backups when their retention period ends.
Transparency and trust
What we do for your security
No message reading
We never read your message content. Only automated processes for delivery have database access.
Automatic deletion
Data is automatically deleted according to the specified time. We don't sell or share your information with third parties.
Minimal metadata
We store only the metadata needed for delivery: the recipient's email and phone, details of senders without an account, delivery and expiry times and file sizes. Content is end-to-end encrypted.
GDPR compliant
We comply with GDPR and other security standards. You have the right to delete your data at any time.