Microsoft has announced that it will introduce message encryption for its cloud-based Office 365 service in early 2014.
Dubbed Office 365 Message Encryption, the system will automatically encrypt email to anyone outside a company firewall. All replies and forwards to that message will also be automatically encrypted before they are returned.
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Shobhit Sahay, product marketing manager on the Microsoft Exchange team, wrote in an Office 365 blog that it will be possible to send sensitive business communications with an additional level of protection against unauthorised access.
He said that the feature will debut during the first quarter of 2014, and will be free to Office 365 E3 and E4 users. It will also be included in the standalone version of Windows Azure Rights Management.
The move is widely being seen as Microsoft's reaction to former NSA contractor Edward Snowden's revelations that US and UK intelligence organisations were capturing and storing emails. Other companies, such as Yahoo and Google, have also taken steps to secure email and messaging traffic.
Yahoo has announced that it will use Secure Sockets Layer to encrypt email connections on January 8 and encrypt all information flowing between data centres by the end of the first quarter in 2014.
Google also announced recently that it was employing 2048-bit RSA encryption keys on all of its website security certificates, which are used to set up encrypted communications between a web server and web browser.
Microsoft needed to come up with an answer of its own, particularly as its cloud-based offerings were already being flagged by EU regulators who are concerned that under terms of the US Patriot Act, Redmond would have to hand over European data stored in its servers. The major US cloud suppliers are concerned that US spying stories are damaging their business, and offering to encrypt traffic is seen as one way of avoiding this sort of snooping.