Introducing File Sharing on LOCK.PUB

Starting today, you can share password-protected files on LOCK.PUB. We've supported 9 content types — links, memos, chat rooms, polls, and more — but file sharing has been the most requested feature, and it's finally here.

What's the Feature?

LOCK.PUB file sharing has these characteristics:

• File contents never in plain text — your file rests as ciphertext, and it takes your password to turn it back into a file
• No sign-up required — share files securely in 30 seconds
• All file types — PDF, Excel, Word, images, videos, ZIP, anything
• Free — even anonymous users can try it

Why We Built It

To share a file before, you had to use messengers, email, or cloud storage. But each has problems:

• Messengers: The file stays in the chat history on every device; risk of sending to wrong chat
• Email: 25MB limit; stored as plaintext on mail servers
• Cloud Drive: Sign-up required; the cloud provider can access your files

LOCK.PUB file sharing solves all of these. No sign-up, password-protected, encrypted.

How It Works

1. Upload: Your file is AES-encrypted with a key derived from the password and stored on the server
2. Storage: We hold the encrypted object, never a browsable copy of your file, and we never store your password — only a salted verifier that can check it
3. Download: The file is decrypted only when someone enters the correct password, and you can set an expiry date (Pro) so the link stops working after the day you choose

The key that turns the stored ciphertext back into a file is built from two things: your password and a server secret that never sits in the database beside it. We never keep a copy of your password — which is also why there is no reset. Guard it, and the file opens for exactly the people you chose and nobody else.

Free vs Pro

Anonymous users can also try it with a 2MB per-file and 5MB monthly upload limit.

Try It Out

Head to lock.pub and select the "File Share" tab — you can use it right away.

Send feedback or bug reports via GitHub or X (Twitter). LOCK.PUB keeps evolving thanks to user input.