Facebook trials end-to-end encryption for email to end-users

Facebook on Monday announced a new experimental privacy feature that will allow it to encrypt notification emails sent by the social network to users.

Facebook’s one billion users can now add an OpenPGP public key to their profile via a desktop browser, which they can do from the account’s Contact and Basic Info page.

Setting up the public key allows emails from Facebook to be encrypted from its own servers to the user’s email account, closing one gap — albeit a minor one, given it only pertains to Facebook email notifications — that could be exploited by anyone who gains access to an email provider’s servers, such as law enforcement agents with a warrant or a skilled c.

“Whilst Facebook seeks to secure connections to your email provider with [Transport Layer Security encryption], the stored content of those messages may be accessible as plaintext (with attachments) to anyone who accesses your email provider or email account,” said Facebook’s security team.

According to Google’s Transparency report, request by governments worldwide for access to user accounts (such as Gmail) has climbed steadily over the past three years to just over 50,000 in the six months to December 2014, with a fifth of requests coming from the US. Requests from Australia reached just under one thousand in the same six month period.

Potentially one of the biggest contributions Facebook could make to enhancing privacy is by educating people about PGP public key encryption, which online rights group Electronic Frontiers Foundation (EFF) notes is difficult to understand but very effective at protecting the content of messages.

People interested in adding a PGP public key to their Facebook account can read the EFF's instructions on how to set up PGP on Windows and Mac, as well as a writeup about its benefits and limits.

The scheme may also help users detect phishing emails that attempt to steal user credentials since Facebook will be able to sign outbound messages used its own key.

For its own implementation, Facebook used GNU Privacy Guard or “GPG”, which the company donated $50,000 to earlier this year. Facebook’s notifications are encrypted with RSA or ElGamal algorithms, and it says it is “investigating the addition of support for GPG's newer elliptic curve algorithms in the near future.” Additionally, it’s also looking at how to support public key management on mobile devices.

This article is brought to you by Enex TestLab, content directors for CSO Australia.

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