Security
Your files move. Your privacy stays.
End-to-end encryption, temporary sessions, and no server file storage. Here’s what those choices protect—and where you still need to take care.
The same encryption on every plan.
Content
Encrypted before it leaves your browser.
PairSend encrypts files and text at the application layer before sending them. The receiving browser verifies and decrypts the content.
The service that sets up the connection does not need your plaintext to do its job. The encryption model treats the transport as untrusted, rather than relying on a network provider to keep the content private.
Paid plans use the same encryption as the free plan. Upgrading adds saved devices and more daily sending capacity.
Lifetime
A transfer session, with an end.
PairSend’s backend coordinates the connection using temporary session information. It does not store plaintext files or encrypted file copies for later download.
Sessions have a hard expiry. Session keys and local reconnect records are cleared when that time is reached. A reconnect window is limited to the same device and cannot extend the session’s lifetime.
Downloaded files are yours to keep.
Ending a session does not erase files from either device. Original files and downloaded copies remain wherever you saved them.
Device trust
Remember the device. Start a fresh session.
Saving a trusted device is optional and happens after a live encrypted connection. Your browser keeps the device’s verification key and label locally; it does not keep a reusable session key for future transfers.
Future requests are signed and checked against that saved record before an approval prompt appears. Both browsers must be open, and each accepted request creates a fresh session.
Optional Secure Reconnect uses a passkey to protect local reconnect material where supported. It applies to returning on the same device, and is separate from saving a trusted device for future handoffs.
Only trust devices you control. Forgetting a device removes it from this browser; clearing browser data also removes your local saved-device records.
Boundaries
Know what encryption can protect.
Designed to protect content from
- Passive observers watching network traffic.
- Connection services that observe and relay messages.
- Transport providers carrying encrypted content.
Outside that protection
- A compromised device or browser.
- A malicious server delivering modified website code.
- A code shared with the wrong person, or a recipient keeping a copy.
Treat pairing codes as private access. Check who you’re connecting with, keep your browser up to date, and only send files to a device you trust.
See how a transfer works