Mozilla has launched an online service for private sharing of encrypted files between two users. It’s called Send, and it’s meant to ensure users’ shared files do not remain online forever.

Encrypted file sharing: How does it work?

Send allows users to upload a file (up to 1GB), it encrypts it, and provides a link that can be sent to the person for whom the file is intended.

The link will “expire” after 1 download or 24 hours – whichever comes first – and Mozilla says that all the sent files will be automatically deleted from the Send server.

“When you use Send, Mozilla receives an encrypted copy of the file you upload, and basic information about the file, such as filename and file size. Mozilla does not have the ability to access the content of your encrypted file, and only keeps it for the time or number of downloads indicated,” the company claims.

John Gruen, Mozilla Product Manager explained to Help Net Security that Send uses the Web Cryptography JavaScript API with the AES-GCM algorithm for client side encryption and decryption, and that the service works in all browsers that support the latest Web Cryptography JavaScript API.

I’ve tested the service on Safari, Firefox and Chrome, and it works like a charm on the latter two. Naturally, both the sender and the recipient have to use a browser that supports the API in question.

If you’re going to use the service, know that anyone you provide with the unique link to your encrypted file will be able to download and access that file, so be careful to whom you actually provide the link.

Send has been released as part of the company’s Test Pilot, a site where the Mozilla team publishes experimental features that may or may not end up in Firefox or some of its other software offerings, or even continue their life as standalone solution.