Encrypt messages - Outlook - Microsoft Office Online

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Encrypt messages

Applies to: Microsoft Office Outlook 2003

Encrypting a message protects the privacy of the message by converting it from plain, readable text into cipher (scrambled) text. Only the recipient who has the private key (private key: The secret key kept on the sender's computer that the sender uses to digitally sign messages to recipients and to decrypt (unlock) messages from recipients. Private keys should be password protected.) that matches the public key you used to encrypt the message can decipher the message. This is a separate process from digitally signing a message.

Show Encrypt on a per message basis

In the message, click Options .
Click Security Settings.
Select the Encrypt message contents and attachments check box.
To change additional settings, such as choosing a specific certificate to use, click Change Settings.
Click OK three times.

Show Tip

If you use Microsoft Word as your e-mail editor, there is a quick way to encrypt a message. With the new message open, on the E-mail toolbar, click the Button image

button.

Show Encrypt all messages

In the main Outlook window, on the Tools menu, click Options, and then click the Security tab.
Select the Encrypt contents and attachments for outgoing messages check box.
To change additional settings, such as choosing a specific certificate to use, click Settings.

Notes

In order to send encrypted messages over the Internet, you need to swap certificates (certificate: A digital means of proving your identity. When you send a digitally signed message you are sending your certificate and public key. Certificates are issued by a certification authority, and like a driver's license, can expire or be revoked.) (.cer (.cer file: A file that contains a certificate with a public key but no private key. Import the .cer files into Contacts by clicking Import in the Certificates tab, and then use the certificate to send encrypted messages.) files) with the recipient. You can do this a number of ways. For example:
- Send a digitally signed message. The recipient adds your e-mail name to Contacts and in doing so also adds your certificate.
- Send a message with your .cer file attached or give a floppy disk with the .cer file. The recipient can import the .cer file into your contact card.
- Create a contact card with your .cer file, and then send the contact card.
- Publish your certificate to an LDAP (Lightweight Directory Access Protocol (LDAP): A protocol that provides access to Internet Directories.) directory or another directory that is available to the other person.
- Post the certificate on a share that is available to the other person.
If your system administrator has set up security for your network using Microsoft Exchange Server, it is not necessary to swap certificates.
3DES (3DES: An encryption algorithm based on the Data Encryption Standard (DES). Triple DES (3DES) repeats DES three times. Consequently, 3DES runs slower than standard DES. However, it is more secure.) is the default encryption algorithm. Encryption strength is no longer restricted by the United States government. Microsoft Outlook uses the RC2 algorithm by default when running on a 40-bit operating system that does not have 128-bit encryption capabilities.