Message encryption in MS Outlook 2010

Sometimes there is a need for additional protection of your private messages from other people. There may be plenty of reasons for that. Starting with private ones, like writing a personal letter to a close friend, or telling your family where you usually keep your keys. Also in more formal and serious situations, like mailing a check to pay a bill, encrypted e-mails are like sealed envelopes, as opposed to postcard-like availability of unencrypted e-mails.

MS Outlook 2010 message encryption protects the privacy of the message by converting it from a readable plaintext to scrambled ciphertext. Only recipients who have a private key - the key stored on a sender's computer, used by the sender to digitally signing a message, and to decrypting a message from a recipient, - matching a public key - the key that the sender gives to the recipient, who, in turn, can verify the sender's signature, and confirm that no changes have been made to the message; the recipient also uses this key to encrypt a message to the sender - used for decoding the message, can decrypt a message. Any other recipient without the proper key will only see a garbled text.

In order to send and review encrypted messages, both the sender as well as the recipient must share the digital ID - it contains the private key stored on the sender's computer and a certificate with a public key. The certificate is sent with a digitally signed message. The recipient saves the certificate and uses the public key to encrypt the sender's messages. It means that both the sender and recipient must send a digitally signed message, which allows adding the certificate to Contacts. From then on it is possible to send encrypted messages similarly to sending not encrypted ones. You can learn more about it here.

Before it is possible to start encrypting and decrypting messages, both the sender and recipient should get a personal mail certificate. Messages encrypted with such certificate ensure the recipient about the authenticity of an e-mail, and keep it unreadable to others. Free certificates can be obtained from here by filling a simple form.

Let's now proceed to encrypting a single message.

Step 1.

In a new message in Options click More Options field.

Fig.1. Options in a new message.

Step 2.

In the next window click Security Settings tab.

Fig.2. Security settings tab.

Step 3.

In the newly open window click Encrypt message content sand attachments.

Fig.3. Encrypt message contents and attachments.

Now all that's left is composing and sending the message.

It is also possible to set Outlook to encrypt messages globally by default. In that case, composing and sending messages is the same as with unencrypted messages, but the sender and recipient will need to have a digital ID in order to decrypt the message.

Step 1.

In File menu (Backstage View) click Options, the find Trust center and Trust Center Settings.

Fig.4. Trust Center Settings.

Step 2.

In the new window click E-mail Security, then mark the Encrypt contents and attachments for outgoing messages.

Fig.5. E-mail Security.

Step 3.

Confirm the changes clicking Ok.

From now on all the outgoing messages are encrypted.

If the recipient's e-mail settings do not support message encryption Outlook will notify and suggest sending an unencrypted message.