Message Encryption in Office 365Microsoft quietly announced in February 2014 that its Office 365 Message Encryption service will be available to all companies with the E3 and E4 subscriptions. There is no longer a separate charge to get this encryption service; instead, message encryption is available at no additional cost to those with E3 and E4 subscription plans, while those with E1 only have to pay $2 per user per month.

How does Office 365 use encryption? There are two methods: implementing encryption in the service, or offering it as a customer control. How does it work? First, the message is taken from plain text and changed into unreadable ciphertext. This can be done by the sender’s machine or through a central server while the message is en route. In transit, the message remains in ciphertext, until it is received by the recipient and decrypted, either by the recipient’s device or a central server.

There are three types of available encryption for email protection: Office Message Encryption (OME), Secure/Multipurpose Internet Mail Extensions (S/MIME), and Information Rights Management (IRM). Each of them are most effectively utilized in different scenarios. Learn more about the different encryption types in Office 365.

Encrypted Office 365 messages are stored in the recipient’s mail system, not the Microsoft servers. The message is delivered as an HTML file attachment, and the recipient must sign in or use a passcode to view the message. Instructions are included with the encrypted email. Here’s more detailed information on sending, viewing, and replying to an encrypted message.

While this encryption service has been made readily available, the setup is more complicated than simply checking a box. One of the prerequisites is having a subscription for Azure Rights Management set up for Exchange Online or Exchange Online Protection. Additionally, Exchange Online Remote PowerShell is required for set-up, and the Rights Management Services online key-sharing location must be configured in Exchange Online. Here’s a detailed set of instructions on setting up message encryption in Office 365.

Find out more about how message encryption in Office 365 works on Microsoft’s FAQ page.

Are you interested in Office 365 Message Encryption? Do you have more questions about how it works and why you need it? Send us an email or give us a call: 502-240-0404.