Mozilla releases Firefox Send, a free encrypted file transfer service

Mozilla has released the finalized version of Firefox Send, its free encrypted file transfer service that allows users to share files from any browser.

With Send, users can securely share files of up to 1GB in size (up to 2.5GB if they sign up for a free Firefox account). Recipients don’t have to have a Firefox account to access the file, just the link.

About Firefox Send

A beta version of the service was released in August 2017. At the time, users were limited to sending files up to 1 GB and the created link to the file would “expire” after 1 download or 24 hours (whichever comes first).

This first official version offers more security controls. Users can choose whether:

• Their link to the file will expire after 1, 2, 3, 4, 5, 20, 50 or 100 downloads
• Their link to the file will expire after 5 minutes, 1 hour, 1 day or 7 days
• To protect the file with a password for an extra layer of security.

The service runs atop Google’s Cloud Platform and uses the Web Cryptography JavaScript API with the 128-bit AES-GCM algorithm for client side encryption and decryption. It works in all browsers that support the API, but some have not implemented it yet (e.g., some mobile browsers).

“Mozilla receives an encrypted copy of the file you upload but we cannot access the content or the name of your encrypted file,” the organization explains in the service’s Privacy Notice.

“By default, files are stored for a maximum of either 24 hours or 7 days. If you choose a download cap, the file can be deleted from out server sooner.”

The document also points out that Mozilla receives the IP addresses of the uploaders and downloaders and retains them for 90 days.

“Although we develop our services in ways to minimize identification, you should know that it may be possible to correlate the IP address of a Send user to the IP address of other Mozilla services with accounts; and if there is a match, this could identify the account email address,” Mozilla informs.

Users who don’t trust Google’s Cloud Platform have the option of running their own instance on another cloud service or local machine. The requirements for each scenario are listed on the project’s page on GitHub.

Mozilla also shared that Firefox Send will be available as an Android app in beta later this week.