Coffer: share private files without making the other person sign up for anything
Coffer is end-to-end encrypted file and note sharing with an optional private drive. Files are encrypted in your browser with AES-256-GCM before they are uploaded, and the key travels in the part of the link after the #, which browsers never send to a server. The server stores only ciphertext: it cannot read a single file name.
Send files
Drop files or paste a note and get a link. Whoever opens it needs no account and installs nothing: the file is decrypted in their browser. Links can expire, burn after a number of views, carry a password, and be revoked.
Request files
Need someone to send you a file? Create a secure upload link. They upload without an account, their browser encrypts each file so that only you can open it, and the link can do nothing else.
Keep a drive
Sign up with an email and a password for encrypted folders, notes and a list of every link you have shared. Folder links follow the folder as it changes, and can let the people you send them to add files of their own.
Open source
Coffer is free software under the AGPL and runs as a single container. Source on GitHub. Read the security model, the terms and the privacy policy.
Coffer needs JavaScript to encrypt and decrypt in your browser.